Ben decides to throw Kate a birthday party and invites her wild friend from high school; Tommy tells Kate why he hates Molly.
When Ben and Kate find a 15-year-old envelope with a scavenger hunt in it, they decide to complete it; B.J. asks Kate to help her get some stuff back from an ex.
Kate wants Ben to be prepared for potential emergencies; Ben's crazy ex visits; B.J. starts developing feelings for her boss.