Pembleton and Bayliss investigate the S&M-related murder of a young woman, which initially makes Bayliss uncomfortable, but ultimately forces him to confront his own darker side. The detectives eventually learn the woman was killed by her neighbor, who accidentally choked her to death during rough sex. In another case, Lewis and Crosetti (Jon Polito) pursue a suspect who killed a man over a $1.49 pen. Lewis is deeply shaken by the seemingly pointless motive. Meanwhile, the despairing Munch crashes the first date of Bolander and Linda, ruining their evening by venting his romantic woes, until Linda offers him words of encouragement.