Milwaukee, 1948. Joe Sonntag, ace investigator for the police department, faces a riddle: a lovely young woman is found dead at the zoo, near the lion cages, lying in a bed of ferns. She has been carefully laid out there, her arms folded. Nearby, a lioness prowls her cage. Plainly, whoever put her there cared for her. Detective Lieutenant Joe Sonntag, the brains of the Milwaukee Police Department, tries to get the scoop on her: why she was placed there in that fashion, and who or what killed her. A lucky break puts him on the trail to a summer camp outside of the city, where girls discover how to be independent women. Joe Sonntag knows plenty about the criminal mind but doesn't know beans about women. His wife, Lizbeth, likes to remind him of it. She's got her own ideas about this deal. The other detectives, young Frank Silva and urbane Eddy Walsh, think they have women figured out and that Sonntag is a bit retarded when it comes to skirts. Between them the follow leads that take them in startling directions. They find a mysterious world none of he knew about, where death can be a mercy and compassion can inspire murder.