In 1724, Thomas Newton is cast out of his home by his aristocratic father. Desperate to make a new life for himself, he heads to London. Through a string of intimate encounters, he enters the underground world of male-male desire.

Soon enough, Thomas meets Margaret Clap, who runs one of the male brothels. Without a child of her own, "Mother Clap" finds herself drawn to Thomas. She offers him a place in her house, but also a place in her heart.

Thomas's homecoming is too brief. The Society for the Reformation of Manners, a group of Christian zealots, begins raiding the Molly houses. They plan to force the arrest, conviction, and execution of any man guilty of "crimes against nature."

When Margaret Clap's house is raided and Margaret herself is arrested, Thomas has to make the most difficult decision of his still young life, one that could destroy everyone around him in a desperate effort to save them.