This is raunchy sci-fi from one of my favourite authors. It's about a 'liesure-out', a fellow who measured bright enough to qualify for the good life in the tightly controlled near-future society into which he was born, but who has too many antisocial factors on his evaluation to qualify for a position of real responsibility. At an early age, he took the option to live in a perpetual world of make-believe, and became a 40's-era play-detective in a part of New York where tourists go to watch people like him acting out their adopted lifestyles.
It's an easy - if boring - life for the liesure-out until someone turns up to hire him for a real gig as a real detective. He finds himself unable to refuse once various parties get the idea that he's on the job, and events sweep him along for one very bizarre journey of sex, violence, and space-faring historical significance.
It's a great read, in the tradition of the author's other sci-fi (see the Armageddon Crazy, The Feelies, Vickers, the DNA Cowboys books, etc). Farren's work is one of my major influences in trying my own hand at fiction.