Things aren't going well for Slippery Jim diGriz. First there was the robbery of the Mint on Paskönjak that went terribly wrong, and then that little matter of a death penalty, and an extremely unpleasant execution after that. And last but not least, there's the deal Slippery Jim cuts with the authorities, which, on reflection, doesn't look much better than slow death.
In exchange for his life, Slippery Jim must retrieve a missing alien artifact from the planet Liokukae - a dumping ground for the Galactic League's misfits, murderers, maniacs, and the incurably obnoxious. Under cover as the leader of the rock band The Stainless Steel Rats, Slippery Jim violates every law of the land - including the musical ones. He has 30 days to bring back the artifact... or the slow-acting poison the League has fed him will kick in, and Slippery Jim diGriz will be history.