As Eddie gets excited about becoming a father, Lucy catches the gambling bug.

When a perverted arsonist strikes Tacoma, the TPD and the TFD must put aside their rivalries to solve the case. To everyone's surprise, the two crews discover they are not as different as they think, but how long can the lovefest last?

Councilwoman Price tells Terry to find the author of an anonymous tell-all blog which has been exposing Tacoma FD's embarrassing little secrets. Also, the Chief becomes a country fan, and the gang fights over which show to watch.

When Eddie Penisi, Sr. (Joe Pantoliano) shows up at the station unannounced, Eddie and Terry vie for his approval. The rest of the gang embraces their inner nerd playing D&D, but their dungeon master Andy becomes drunk with power.

Lucy is hit in the throat during a rescue, which leads to peer counseling sessions and family insecurities being exposed.

Ike's mean twin brother Mike pays him a visit and asks for a life-changing favor; the crew take DNA tests; Granny discovers his Jewish heritage; Terry is devastated to learn that Lucy's genes are more Penisi than McConky.

The crew respond to a fire in a haunted house.