You might have gathered by now that I'm not particularly fond of Baxendale's writing. Nor, it appears, is anyone else. This is one of the least-worst of them though. A bunch of soldiers, imprisoned on a planet that they were scouting because if they leave it they decompose instantly, decide, for no reason other than that they're dying of radiation sickness and they're understandably pissed off, that they want to destroy the peaceful colony that they started out on.
I suspect you can probably write most of the rest of the plot yourself; there is some more to it, but it's mainly there to explain the doomsday weapons and, indeed, how everything ended up like it is in the first place.