The Confession

An attractive young woman drives through the countryside, thinking about a man, stopping to change from a tee-shirt to a sheer dress. She enters a prison as a visitor, is subject to a careful search, and is placed in a plain room with cheap metal furniture. A guard brings into the room the man she's been thinking about, removes his handcuffs, sits him down in a chair across from her, and hands him a towel and bar of soap. The guard leaves. She asks the prisoner what happened, and he begins an explanation. Where does this lead?