An old flame of Harry's drops by to renew their relationship but neglects to tell him she's married. Meanwhile, Dan bails out of bowling night with the staff so he can have sex with his latest fling, but he and Harry end up out on the ledge when Mac, Christine, Bull, and Roz go looking for them.

The gang joins Roz in a therapist group she's required to attend to temper her hostile attitude at work, which turns into a police situation when a young, inexperienced gangbanger holds everyone hostage.