When Freddie Noon is caught in the act of burgling a research laboratory by a couple of the doctors who work there, he is persuaded to act as guinea pig to test the experimental drug they are working on, rather than get sent to prison. The drug was supposed to help combat skin cancer by eliminating skin pigment, unfortunately when given to Freddie it not only eliminated Freddie's skin, but also the rest of him, rendering him invisible. An invisible burglar, the possibilities are endless. But so are the problems. Freddie and his girlfriend, Peg, are chased by various people who all have the same idea, harnessing his invisibility for their own evil plans.
Thanks to Westlake's great ability with putting together great caper stories, the subplots are amusing and quite entertaining, but when you get to the end you get the feeling that the potential has not been reached. Although not an uproariously funny book, its tone is light and the humour is constant, at times subtle and usually quite clever.
If it's light reading you're after and prefer entertainment over finding a deeper meaning of life, I think you'll enjoy this book. A good example of the humour of Donald Westlake can be found in a surgeon general's warning on the inside front flap stating that "Reading Donald E. Westlake may lead to shortness of breath, prolonged chortles, outbreaks of hysterical laughter, and sudden, drop-dead surprises."