SOLVED. Children's (MG?) Fantasy-- Siblings find a centuries-old boy in their house. [s]

[Chelsea]

I read this book around 2005 +- a few years, but I feel like at the time I thought it was older. The basic plot as I remember it is that two kids (a brother and sister?) move into a new house and realize that there is a space between the walls of two rooms. They assume there's a secret crawlspace, and when they find it they wake up a boy who's been in there for centuries.

Tidbits I remember:
- They figure out the space is there because the rooms measurments are weird.
- One of the kids says "you don't know what a computer is?" and the ancient boy says "well, I expect it computes."
- I want to say it takes place in the UK or New England. Could be wrong.
- I felt at the time like the style was kind of slower/old-fashioned. (Although obviously not too old-fashioned since computers were in it.)
- I think there was something in there about finding old glass bottles, but I can't remember how it connected to the plot.

[Audrey]

Skellig by David Almond?

[Chelsea]

Audrey wrote: "Skellig by David Almond?"

It isn't that, although Skellig looks intriguing.

[Audrey]

Oh well, I hope you find your book! It sounds very interesting.

[Rainbowheart]

Was the boy a ghost?

Was there any explanation about why he was in the crawlspace?

[Chelsea]

Rainbowheart wrote: "Was the boy a ghost?

Was there any explanation about why he was in the crawlspace?"

I feel like there was something about the space being built to hide monks (?) or something along those lines, and he was placed there intentionally. It kind ofreminded me of the underground railroad but it definitely was a different historical people-in-hiding reason. Some kind of magic/alchemy put him to sleep/suspended animation/something so that he hadn't aged since they found him. I can't remember how long he'd been there.

[Rainbowheart]

Sounds like a priest hole.

In which case, it probably took place in England.

[Chelsea]

Rainbowheart wrote: "Sounds like a priest hole.

In which case, it probably took place in England."

Yes that sounds right. Good job narrowing it down for me! Thinking on it more I'm like 90% sure the boy was involved in alchemy somehow and that's what kept him alive.

[Chelsea]

SOLVED!
It's Doctor Illuminatus by Martin Booth. Rainbowheart's comment about Priest Holes helped me find it in Google Books. Thank you!

[Rainbowheart]

Awesome, glad you found it!

Doctor Illuminatus for the link.