Cullin's latest (after The Cosmology of Bing) is a brief but incisive account of a Tucson teacher's descent into the lurid, furtive world of illicit gay sex, which lands him in the wrong place at the wrong time when a murder is committed. John Connor is the ordinary, sensitive narrator whose descent begins when he finds himself frequenting adult video stores after his sex life with his wife sours. Despite his guilt, Connor becomes a regular at the restrooms in public parks where he finds like-minded men for quick, anonymous sex. Cullin's grim description of Connor's increasingly risky encounters turns lyrical when Connor hits it off with a fellow middle-class lover he calls Polo, but the tone shifts when a murder occurs during one of their meetings in a public restroom. Stricken by guilt after fleeing, Connor approaches a Tucson detective, not knowing that the police have already connected him to the crime. When his arrest becomes imminent and his wife leaves with their two children, he goes underground, living homeless on the edge of Tucson as he tries to puzzle his way through his bizarre dilemma. Cullin packs a lot of literary power into relatively few pages. As a crime narrative based on a true story, the book is a chilling if somewhat dated tale of a misstep morphing into free fall; as a literary character study, Connor's attempt to come to terms with his situation is both haunting and compelling. Perhaps best of all is Cullin's poetic but economical description of the plight of the homeless as John Connor enters their world in this memorable novel. (Sept.)