The eighth Rat book, and the third in the 'prequel' sequence, following A Stainless Steel Rat is Born and The Stainless Steel Rat Gets Drafted.
Slippery Jim is caught red-handed when he tries to rob the mint in Paskönjak. He is presented with a simple choice: a horrible death, or a job for the Galactic League. The League want Jim to go to the planet Liokukae and bring back a missing artefact - the only known evidence of an alien life-form ever found.
To ensure that Jim doesn't try to escape, he is given a slow-acting poison - he's got 30 days to return with the artefact, and receive the antidote, or he'll die. Liokuke is a colony where misfits and maniacs are sent, so to ensure a warm welcome and safe passage around the planet, Jim arrives with three League agents, disguised as a rock band sent to entertain the inhabitants. But as time passes - and Jim's life expectancy is reduced - the mission becomes less about recovering the artefact, and more about liberating the planet.