Eight teenagers who go camping in the bush for a few days, only to return and find that Australia had been invaded by an unknown enemy. They then spend the next five books fighting a guerrilla war against the invaders. The story is narrated by Ellie, who is elected to keep a written record of what happens to them. However, her record quickly turns into something closer to being a diary.

I read this at a much earlier age than I was supposed to - at about eight or nine rather than fourteen or fifteen. As such, it is particularly notable to me because it was the first thing I ever read which contained an overt description of characters having sex. In a later volume (I no longer remember which), Lee and Ellie, between whom sexual tension has been simmering since the very beginning, finally get it on while squatting in an abandoned house in some heavily war-damaged rural Victorian town. In a move that is incredibly cliched, though I didn't realise it at the time, Lee pulls an ancient condom from his wallet that dates from a long-forgotten sex ed lesson several years previously. Sex proceeds awkwardly but magically, for it is their first time. The next morning they are embarrassed and forbear to tell the others, though naturally it all comes out eventually. It's very typical and quite unoriginal, but I remember being positively glued to the page, saucer-eyed, infinite vistas of previously-unimagined possibilities opening up within my mind. I was as naive and prudish as any child, and though I understood the mechanics of sex (or at least I think I did), the idea that anyone could write about it was mind-blowing.

Later on, it was also the birth of a long friendship resulting from a giggly moment with a fellow bookworm ("did you read the bit where... where they have sex?") and for that reason alone I have much to thank it for.

The author's bio claims that John Marsden is "the world's most successful author of teenage fiction." Personally I think that's probably not true, but as YA lit goes, this is pretty damn good. The concept is singularly brilliant: there is something about the thought of one's country being invaded that does something to one. Maybe people from any country feel like this, but there has never been a war on this soil (the bombing of Darwin in WWII doesn't count because that was from the air), and in general Australia is so peripheral to international affairs that the thought just never crosses our minds. It's odd: the thought of being invaded, of being raped and pillaged and bombed to bits and ground under the cruel yoke of occupation seems to have a sort of vicarious appeal - the shudder of dread is mixed with a shiver of excitement. The themes are just the right complexity for the age group; the ending is satisfyingly unhappy and confrontingly realistic, and although the moral and ethical discussions are naive, they are, I think, fairly accurate and convincing portrayals of how someone that age would think.

Unfortunately, it is kind of disgustingly YA. When I first read it, I loved it so much I saved my pocket money obsessively for a year or so until I could buy the boxed set, but then whenever I tried to read them again I hated them and cursed my innocent stupidity and the wasted $70 (it was a massive amount of money back then). The prose is irritating as hell at times, and reading about teenagers and their stupid emotions and stupid acne and stupid immaturity has never really appealed to me. Nonetheless, and rather surprisingly, I'm enjoying reading them again - it's a lot of fun.