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Doctor Who Target Books (Numerical Order) #36
Doctor Who and the Invisible Enemy
A mysterious cloud drifts menacingly through space...
A sudden energy flash and the Doctor is infected with the Nucleus of a malignant Virus that threatens to destroy his mind.
Meanwhile, on Titan, human slaves prepare the Hive from which the Virus will swarm out and infect the universe.
In search of a cure, Leela takes the Doctor to the Foundation where they make an incredible journey into the Doctor's brain in an attempt to destroy the Nucleus.
But can the Doctor free himself from the Nucleus in time to reach Titan and destroy the Hive? Luckily he has help — in the strangely dog-like shape of a mobile computer called K9...
A sudden energy flash and the Doctor is infected with the Nucleus of a malignant Virus that threatens to destroy his mind.
Meanwhile, on Titan, human slaves prepare the Hive from which the Virus will swarm out and infect the universe.
In search of a cure, Leela takes the Doctor to the Foundation where they make an incredible journey into the Doctor's brain in an attempt to destroy the Nucleus.
But can the Doctor free himself from the Nucleus in time to reach Titan and destroy the Hive? Luckily he has help — in the strangely dog-like shape of a mobile computer called K9...
112 pages, Paperback
First published March 1, 1979
5 people are currently reading
263 people want to read
About the author
Terrance Dicks
327 books220 followersTerrance Dicks was an English author, screenwriter, script editor, and producer best known for his extensive contributions to Doctor Who. Serving as the show's script editor from 1968 to 1974, he helped shape many core elements of the series, including the concept of regeneration, the development of the Time Lords, and the naming of the Doctor’s home planet, Gallifrey. His tenure coincided with major thematic expansions, and he worked closely with producer Barry Letts to bring a socially aware tone to the show. Dicks later wrote several Doctor Who serials, including Robot, Horror of Fang Rock, and The Five Doctors, the 20th-anniversary special.
In parallel with his television work, Dicks became one of the most prolific writers of Doctor Who novelisations for Target Books, authoring over 60 titles and serving as the de facto editor of the range. These adaptations introduced a generation of young readers to the franchise. Beyond Doctor Who, he also wrote original novels, including children’s horror and adventure series such as The Baker Street Irregulars, Star Quest, and The Adventures of Goliath.
Dicks also worked on other television programmes including The Avengers, Moonbase 3, and various BBC literary adaptations. His later work included audio dramas and novels tied to Doctor Who. Widely respected for his clarity, imagination, and dedication to storytelling, he remained a central figure in Doctor Who fandom until his death in 2019, leaving behind a vast legacy in television and children's literature.
In parallel with his television work, Dicks became one of the most prolific writers of Doctor Who novelisations for Target Books, authoring over 60 titles and serving as the de facto editor of the range. These adaptations introduced a generation of young readers to the franchise. Beyond Doctor Who, he also wrote original novels, including children’s horror and adventure series such as The Baker Street Irregulars, Star Quest, and The Adventures of Goliath.
Dicks also worked on other television programmes including The Avengers, Moonbase 3, and various BBC literary adaptations. His later work included audio dramas and novels tied to Doctor Who. Widely respected for his clarity, imagination, and dedication to storytelling, he remained a central figure in Doctor Who fandom until his death in 2019, leaving behind a vast legacy in television and children's literature.
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Displaying 1 - 30 of 34 reviews
December 31, 2021
Pretty standard Target novelisation during the peak of these being released - it definitely feel like Dicks has a deadline to meet.
The story is most noticeable for the introduction of 'The Tin Dog' K9.
During this era of the show the production team would use popular films as inspiration for serials and this one relies heavily on 1966 'Fantastic Voyage'.
I actually like that it's The Doctor who's been infected by the virus and makes the story much more compelling that it's a clone Fourth Doctor and companion Leela who has to enter a Time Lords brain.
A quick entertaining read that isn't hampered by trying to recreate big movie's on a 1970's TV budget.
The story is most noticeable for the introduction of 'The Tin Dog' K9.
During this era of the show the production team would use popular films as inspiration for serials and this one relies heavily on 1966 'Fantastic Voyage'.
I actually like that it's The Doctor who's been infected by the virus and makes the story much more compelling that it's a clone Fourth Doctor and companion Leela who has to enter a Time Lords brain.
A quick entertaining read that isn't hampered by trying to recreate big movie's on a 1970's TV budget.
July 28, 2021
This is a novelization of the second serial of the fifteenth season of Doctor Who, which starred the most popular, scarf-wearing fourth Doctor, his companion Leela, and introduced the robotic K-9 to the series. It was broadcast in four parts in October of 1977. The book was written by Terrance Dicks, who wrote many episodes of the series himself and even more good novelizations, and this one was based on a teleplay by Bob Baker and Dave Martin. In this story, The Doctor is infected by an evil space virus that threatens to destroy his mind, not to mention plans to swarm out to infect the universe from the Hive being constructed on Titan. He teaches Leela how to get them to the nearest medical center, where they're both cloned and miniaturized and injected into his brain to defeat the virus, much like the film Fantastic Voyage, which was quite popular at the time. Dicks did quite well at presenting Leela as a competent and imposing companion; she was often relegated to the role of eye-candy on screen. He also described the action and settings and creatures effectively, much better than the visual version did since it was anchored by a very low budget for special effects. The story isn't among the best, but it's a short, clever, very entertaining read, superior to the serial in my estimation.
May 23, 2021
After numerous viewings of the episode of Doctor Who "The Invisible Enemy" it was a real kick to read the paper back. In this story, the Doctor gets infected by a virus and it is up to him, Leela, and the wonderful robot dog K9 in his first appearance to rectify the situation and prevent the spread of the contagion. Eerily similar in a way to what we all dealt with in terms of Covid in 2020-21.
April 29, 2021
Not a bad book by any means, but just doesn't grab me either, mostly due to the main antagonist I think.
It is a nice introduction for K9 here, is a good set up for him, possibly making it his strongest appearance, as other stories can have issues with K9's mobility etc, though will see how it goes through this reread :)
The Doctor and Leela are in pretty good form here too really, both showing their different strengths and weaknesses throughout a variety of difference circumstances and environments.
What is detrimental to me though overall is the enemy, where the variety of abilities it seems to have don't necessarily make sense, at least as to where it then can't apparently take action, when at times could in a similar circumstance. The Doctor just shooting at it in his brain to force it to exit the brain didn't necessarily make sense either, it felt like it could have just left that vicinity, and still stayed in there successfully.
And then when it was made giant as such, turned it into a bit or a caricature for me, and for something originally so tiny, it seemed to have a lot of very human dictatorial ideas, when I think it could have been quite alien, like xenomorphs from Aliens, or Tyranids from 40k, with a lot more believability and at the same time adding more to the story.
So overall, just adds up to an okay read, that isn't particularly memorable for me.
It is a nice introduction for K9 here, is a good set up for him, possibly making it his strongest appearance, as other stories can have issues with K9's mobility etc, though will see how it goes through this reread :)
The Doctor and Leela are in pretty good form here too really, both showing their different strengths and weaknesses throughout a variety of difference circumstances and environments.
What is detrimental to me though overall is the enemy, where the variety of abilities it seems to have don't necessarily make sense, at least as to where it then can't apparently take action, when at times could in a similar circumstance. The Doctor just shooting at it in his brain to force it to exit the brain didn't necessarily make sense either, it felt like it could have just left that vicinity, and still stayed in there successfully.
And then when it was made giant as such, turned it into a bit or a caricature for me, and for something originally so tiny, it seemed to have a lot of very human dictatorial ideas, when I think it could have been quite alien, like xenomorphs from Aliens, or Tyranids from 40k, with a lot more believability and at the same time adding more to the story.
So overall, just adds up to an okay read, that isn't particularly memorable for me.
This entire review has been hidden because of spoilers.
December 1, 2020
I wasn't quite sure where this book was going to go when I started, as it was a rather unusual invasive alien story that has first a starship then eventually even the Doctor falling victim to a sentient presence that manifests itself like a virus, spreading from person to person.
But the story fully won we over when it turns out that this is where K9 makes his first appearance in the franchise and the little robot dog is quite the intrepid little companion for the Doctor.
This book also nicely utilizes Leela as a companion with a different set of skills than the Doctor, although it does come with the pain of constant references to her being less sophistical or downright unintelligent, which may be viewed as a little problematic given a modern reading.
The book is still a surprising amount of action including a strange solution to the Doctor using a contrived clone to help fight the alien infection inside him, but it's all in good Classic Doctor Who fun.
But the story fully won we over when it turns out that this is where K9 makes his first appearance in the franchise and the little robot dog is quite the intrepid little companion for the Doctor.
This book also nicely utilizes Leela as a companion with a different set of skills than the Doctor, although it does come with the pain of constant references to her being less sophistical or downright unintelligent, which may be viewed as a little problematic given a modern reading.
The book is still a surprising amount of action including a strange solution to the Doctor using a contrived clone to help fight the alien infection inside him, but it's all in good Classic Doctor Who fun.
November 11, 2025
Doctor Who does Fantastic Voyage. And we get the introduction of K9. This has been a favourite since I was a kid. And it’s one of the first Targets I owned. I’ve still got the actual copy my parents bought me. But like Robots of Death this is a very visual story for me with the running around inside the Doctor’s brain. Terrance does a reasonable job capturing some of that setting, but it’s just so much better on TV
The rest of the plot on Titan and in the Foundation is executed to Terrances usual standard of storytelling. But reading it I noticed some silly plot elements that I gloss over while watching it. Mainly the Killbraken technique of cloning with personality and clothes from a cell. People’s clothes aren’t in their DNA. But then again Doctor Who isn’t a scientific journal.
That aside, it’s still a quick fun read and a favourite story.
The rest of the plot on Titan and in the Foundation is executed to Terrances usual standard of storytelling. But reading it I noticed some silly plot elements that I gloss over while watching it. Mainly the Killbraken technique of cloning with personality and clothes from a cell. People’s clothes aren’t in their DNA. But then again Doctor Who isn’t a scientific journal.
That aside, it’s still a quick fun read and a favourite story.
July 20, 2023
Doctor Who and the Invisible Enemy (1979) by Terrance Dicks is the novelisation of the second serial of the fifteenth series of Doctor Who.
The Doctor and Leela are contacted by a mysterious entity that causes the Doctor to behave strangely. Meanwhile a shuttle’s crew are also infected with the virus. They land on a station and kill the crew. The Doctor and Leela arrive and are confronted by the chaos. They depart for another space station where there is medical help and where the Doctor can be helped. The Doctor and Leela have short lived clones that are shrunk and inserted into the Doctor to confront the virus. It’s all amusingly bonkers.
The serial is notable for the introduction of K9.
Doctor Who and the Invisible Enemy is an amusing read for fans of Doctor Who.
The Doctor and Leela are contacted by a mysterious entity that causes the Doctor to behave strangely. Meanwhile a shuttle’s crew are also infected with the virus. They land on a station and kill the crew. The Doctor and Leela arrive and are confronted by the chaos. They depart for another space station where there is medical help and where the Doctor can be helped. The Doctor and Leela have short lived clones that are shrunk and inserted into the Doctor to confront the virus. It’s all amusingly bonkers.
The serial is notable for the introduction of K9.
Doctor Who and the Invisible Enemy is an amusing read for fans of Doctor Who.
August 3, 2022
Notwithstanding that it introduces K-9 and gives Leela some authentically badass moments, the serial ‘The Invisible Enemy’, written for the screen by Bob Baker and Dave Martin, is an uncharacteristically weak Fourth Doctor story. Kudos to Terrance Dicks’s novelisation, then, for cutting out the dead wood and achieving a degree of pace and suspense. Dicks wrote somewhere in the region of 70 or 80 Doctor Who novelisations, many of them top notch. This one seems a little rushed and there are a couple of continuity errors, but at just 110 pages, it’s a brisk fun read that certainly improves on its source material.
September 29, 2017
Lacklustre - curiously uninvolving novelisation of a televised story that has some excellent things going on. Here they are all merged into a sort of greyish mish-mash - even the usually tiresome K9 is well below par (even for an introductory story) and another writer would have had a field day with the phonetic signs (though it occurs to me that perhaps Dicks had only seen the script and not the screened version, which would account for that).
I started this, read Chapter 1 and then abandoned it for a fortnight...
I started this, read Chapter 1 and then abandoned it for a fortnight...
January 12, 2025
I have a 1984 reprint of a 1979 novelisation of a 1977 television script.
A nice bit of nostalgia with the Fourth Doctor, Leela, and K9, but it’s awful as far as the writing goes. And a shameless rip off of the Fantastic Voyage film for the most part. A plot point stands out that’s so ‘70s it hurts: Leela is immune from the evil psychic virus as she isn’t intelligent enough to be a host … at least the author decided in the end to give her deus ex machina antibodies that could be turned into an antidote. Gosh, they couldn’t get away with that sort of thing these days.
A nice bit of nostalgia with the Fourth Doctor, Leela, and K9, but it’s awful as far as the writing goes. And a shameless rip off of the Fantastic Voyage film for the most part. A plot point stands out that’s so ‘70s it hurts: Leela is immune from the evil psychic virus as she isn’t intelligent enough to be a host … at least the author decided in the end to give her deus ex machina antibodies that could be turned into an antidote. Gosh, they couldn’t get away with that sort of thing these days.
November 4, 2019
The television episodes are bonkers and epic in equal measure -- so bad it's good, yet simultaneously so bad it's painful (giant shrimp, anyone?). Luckily, Terrance Dicks' incredibly stripped-down novelization works to rehabilitate this story as much as possible...he can't save it completely, but he certainly gives it his all. I'm also allowing for an extra glow of nostalgia, as this was one of the first adaptations I borrowed from the library as an excited & newly-minted fan boy.
December 11, 2023
Another faithful adaptation of a Tom Baker story, but without any room for embellishments. Despite the very small page count ( only 110) there are still several typos which should have been picked up and edited out, if this hadn't been rushed out, as so many Target novels were at that time. I must also quickly mention the front cover, which is one of the least interesting of the range.
December 27, 2020
A decent reading by John Leeson. The audiobook itself isn't one of the better Target book adaptations of Doctor Who episodes; it doesn't really add much, and ends up being more of a basic retelling of the serial that was broadcast,
October 15, 2023
As much as I love Leela and the 4th Doctor as a duo I have never really enjoyed this episode. The book is a little better, but the plot still drags. The best part is when the Doctor and Leela have to go into the Doctor's brain unfortunately that part is really short.
November 15, 2024
A very brief retelling of Invisible Enemy that, thanks to Dicks’s economical style, doesn’t really read as bad as it could have been. In terms of background detail, this is a weak effort, but there’s enough to get you investing belief and letting it wash over you. It is, at least, fun.
November 16, 2025
2.5/5
Can't say it's Dicks' greatest (it's pretty on the skimpy side even for him!), but I do think this one is let down a bit on screen by a lack of menace in the special effects department, so I think the sprucing it up helps.
Can't say it's Dicks' greatest (it's pretty on the skimpy side even for him!), but I do think this one is let down a bit on screen by a lack of menace in the special effects department, so I think the sprucing it up helps.
March 21, 2021
An okay story quick read and a good introduction to K9
May 1, 2025
scientifically
preposterous silly fun
dicks cashed his check here
preposterous silly fun
dicks cashed his check here
August 28, 2023
If you're looking for the most average but still enjoyable Target novel, this is for you. The story is almost identical from screen to page, unlike the recent Target entries that have fun embellishments that the authors wish to include. Nope, this might as well be a paperback copy of the screenplay only written in Terrance Dick's signature prose, not that that's a bad thing. Its fun and short and you could probably shotgun the entire thing in an afternoon.
July 26, 2016
**Originally posted on frommybookshelf.com**
An adventure with the Fourth Doctor and Leela, this story also introduced K9 to the Doctor Who universe. In the far flung future, mankind has traveled into space and set up colonies on far off worlds. On a routine expedition to the refueling base on Titan, a moon of Saturn, a crew on a space shuttle comes into contact with a mysterious cloud that is floating through space. Upon contact, the crew become slaves to the Virus and overtake the base in order to convert it to a breeding tank for the Hive. Meanwhile, the Doctor and Leela are in the area and also come into contact with the cloud, and this time the Nucleus takes over the Doctor because of his immense intelligence.
Leela and the Doctor go to the Foundation in hopes of curing the Doctor, only to discover that they are going to have to go on a journey into the Doctor's actual mind in order to rid it of the Nucleus. However, they unknowingly release the Virus into the world and it takes some cunning on the Doctor's part, Leela's hunter instinct, and K9's assistance to defeat the Virus and prevent the Hive from hatching.
I haven't seen this episode, but I'm fairly sure that I could just read right along with what I'd be watching on screen. It certainly doesn't feel like the story was embellished in any way. Part of me almost doesn't want to see the episode either, because I'm fairly sure the limited-budget special effects will certainly not live up to the picture in my mind of how this entire story played out.
An adventure with the Fourth Doctor and Leela, this story also introduced K9 to the Doctor Who universe. In the far flung future, mankind has traveled into space and set up colonies on far off worlds. On a routine expedition to the refueling base on Titan, a moon of Saturn, a crew on a space shuttle comes into contact with a mysterious cloud that is floating through space. Upon contact, the crew become slaves to the Virus and overtake the base in order to convert it to a breeding tank for the Hive. Meanwhile, the Doctor and Leela are in the area and also come into contact with the cloud, and this time the Nucleus takes over the Doctor because of his immense intelligence.
Leela and the Doctor go to the Foundation in hopes of curing the Doctor, only to discover that they are going to have to go on a journey into the Doctor's actual mind in order to rid it of the Nucleus. However, they unknowingly release the Virus into the world and it takes some cunning on the Doctor's part, Leela's hunter instinct, and K9's assistance to defeat the Virus and prevent the Hive from hatching.
I haven't seen this episode, but I'm fairly sure that I could just read right along with what I'd be watching on screen. It certainly doesn't feel like the story was embellished in any way. Part of me almost doesn't want to see the episode either, because I'm fairly sure the limited-budget special effects will certainly not live up to the picture in my mind of how this entire story played out.
November 29, 2012
I am very much enjoying the novelizations of old who that I picked up in Oxford. This one was based on a Leela and Tom Baker episode which was the first episode with K9! I have to say the characterization of K9 in the novel was pretty great, as the little asides the author put in to qualify his comments were most amusing. I've not watched many Leela episodes and what I thought was most interesting from the book was that it really seemed that her and the doctor just didn't like each other very much. They are just at such odds, her with her predator instinct, him with his "massive intellect". The story itself started quite well, an enemy life form invading a base on Titan, the story seemed to get a bit sillier when the Doctor and Leela cloned and then minitarised themselves to go inside the Doctor's brain to fight the virus. This was balanced by K9 being quite lethal. Quite enjoyable and definitely an episode I'd like to see sometime. (Though I fear the effects in my mind are much better than the BBC of the 70s could manage!)
July 9, 2013
As much as I like Doctor Who as a character I must say that some of the plots of the series could easily be made into films without the Doctor being there and would be great as standalone pieces.
One such story is that of The Invisible Enemy. Basically, a spaceship floats into a nearby station and the crew seem to be suffering from a weird kind of virus - or at least that's how it seems so far. However the crew are actually being controlled by a sinister, alien entity - who tries to turn the space station into a control point for his evil schemes. Enter the Doctor and co, who face a race against time to stop the evil, this book also has K-9 in it who is one of my favourite characters of the series. In fact, I do believe that this tale actually introduces the cyber dog.
One such story is that of The Invisible Enemy. Basically, a spaceship floats into a nearby station and the crew seem to be suffering from a weird kind of virus - or at least that's how it seems so far. However the crew are actually being controlled by a sinister, alien entity - who tries to turn the space station into a control point for his evil schemes. Enter the Doctor and co, who face a race against time to stop the evil, this book also has K-9 in it who is one of my favourite characters of the series. In fact, I do believe that this tale actually introduces the cyber dog.
May 21, 2008
The adaption of one of my favorite fourth Doctor episodes.
The Doctor, Leela and in his first appearance, K-9 work to save the universe from an alien germ ( that looks a lot like an evil prawn) before it can completely over run a space station and head for earth.
A cool, cheesy monster, a bit of space opera, some exciting, if questionable science and 'the little tin dog'.
Just reading the story, and being able to imagine it without special effects budget limitations reminded me what a good story it was.
The Doctor, Leela and in his first appearance, K-9 work to save the universe from an alien germ ( that looks a lot like an evil prawn) before it can completely over run a space station and head for earth.
A cool, cheesy monster, a bit of space opera, some exciting, if questionable science and 'the little tin dog'.
Just reading the story, and being able to imagine it without special effects budget limitations reminded me what a good story it was.
Read
April 8, 2009http://nhw.livejournal.com/1007902.html[return][return]Doctor Who and the Invisible Enemy is a case where the novel is basically written as if watching the TV story and writing down what happens on screen. Actually that's not quite fair; the fact that we cannot see the embarrassingly awful monster in the last episode makes it easier to concentrate on the plot, which makes more sense and is a better sf story than I had realised.
July 5, 2015
Fairly serviceable episode made stronger by the novelisation not presenting the villain as a prawn cellotaped to a cardboard box. Standard fare but, given the high standard of the whole Tom era, that standard is one never bettered. Eminently readable in the same way as a box of Turkish delight is eminently eatable. Yum.
April 14, 2008
The Doctor is infected with an intelligent virus; to combat it he and Leela create clones of themselves (!) and shrink the clones (!) so they can fight the virus (!).
Read
August 23, 2008isbn,original
December 10, 2010
Introducing K9 - the best comp ever!
September 27, 2012
Fun, like all the novelizations. A moment from Fantastic Voyage. Leela being badass. K-9! I enjoyed it.
Displaying 1 - 30 of 34 reviews