The Gay Detective (Unabridged‪)‬

Lou Rand's ground-breaking detective novel is one of the first entries in the Gay Detective genre. 

Francis Morely is a fierce but fey private eye who uses insider insights to crack a series of gay murders that have baffled Bay City police. Tiger Olsen is a straight, downwardly-mobile former football payer who takes a job as Morely's sidekick. Seems there's a camera behind a trick mirror in a notorious bathhouse run by the sinister Joe Cannelli, and a few members of high society who think they're too powerful to be blackmailed. 

Will Morley and Olsen have to go undercover as a gay couple and spend a night in the baths to expose the nefarious scheme? Not if the lovely and mysterious Vivian Holden as anything to say about it!