PI can mean many things, but can it really mean a balding, middle-aged redundant lathe operator from a high rise in Luton, Beds? Joe Sixsmith thinks it can. His Aunt Mirabelle thinks you'd have to be crazy to hire him, and Joe's current clients certainly fit the bill. One seems to be confessing to the brutal murder of his whole family; another thinks she's a witch. Alongside them, the two heavies who believe Joe is hiding their illicit drugs seem almost normal.