Fortysomething, photographer slacker, working in IT, living in Greenwich; failed polymath; drinks and eats too much, reads too little...
Slippery Jim diGriz is getting told off by his boss, Inskipp, for stealing while on a previous mission for the Special Corps. Although, staffing a secret inter-galactic space police force with hardened ex-criminals is never going to be plain sailing I'd have thought. While he's being told off two things happen – firstly Jim surreptitiously helps himself to a number of Inskipp's expensive cigars, and secondly Inskipp suddenly disappears. He isn't the first either, a number of people are disappearing from Special Corps headquarters. In true Back to the Future style, somebody is changing the past (present) and causing people to disappear from the present (future). Luckily, there are just enough people left to fire up the time machine, that we didn't know about in any of the previous novels, and fling Slippery Jim, the Stainless Steel Rat, into the past to fight He and return time to its normal course.
What we have here is a Time War. Instead of Time Lords and Daleks it's between Slippery Jim diGriz, and his family and friends, and He, and his nefarious forces. The "He" name gets a little cliched at times. Both our hero and He himself seem to adopt the name without any real agreement. But, it does give Harrison an excuse to play games with He as a name and a pronoun in various forms. It did feel like he was still enjoying it more than me by the end of the book though.
The ending gets a little silly, with lots of people crossing lots of time-lines and creating all sorts of paradoxes left, right and centre. But it's important to remember that this isn't supposed to be a serious work of science-fiction where the time paradoxes are resolved in a way that actually makes sense. Instead this is supposed to be a humorous boys-own adventure, a bill it more than lives up to. Most of the humour is provided as Slippery Jim tries to adjust to life in the 'past' of 1975 on the strange planet of Dirt, or Earth, or whatever it's called (another joke that Harrison doesn't tire of). His attempts to describe everyday things, like TV adverts, are all the usual fun of the 'traveller out of time' trope.