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.

Longing for another female friend, Lucy convinces Chief McConky to transfer firefighter Delilah Dunn to the station; threatened by their female force, the guys on the crew desperately attempt to find a macho match to their energy. Meanwhile, Eddie discovers Linda's wild side, and the boys prank Andy that Chief will buy him a 'five years on the force' anniversary dinner.

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.

Station 24 has been selected to create public service announcements for the city, forcing the gang to work together with the muscled and movie-star handsome C-Team and their newest transfer, Lucy's old friend Delilah (Jessica Lowe). Also, Chief gets an SUV.

Lucy wants new uniforms that fit better after being mistaken for a man. Granny and Eddie join a firefighters a cappella group run by Wolf Boykins.

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.

Terry learns some sexy new dance moves to impress Vicky at the Firefighters' Ball, Ike volunteers to be Andy's wingman, and Lucy discovers that her date is more like his mother than she realized. Meanwhile, Eddie finds out he is up for a big promotion, but will Terry blow it for him before he gets a chance?

As the Firefighters' Ball rages on, things go off the rails for the crew: Terry and Eddie battle it out while stuck in an elevator, Ike deals with an out-of-control Andy who has had a few too many drinks, Lucy struggles to get alone time with her date away from his mother and Wolf Boykins, and Granny finds a way to ease the tension with his date.

The crew respond to a fire in a haunted house.

The holiday season has arrived at the firehouse and everyone is feeling jolly--except Eddie. In order to get good year-end reviews, Lucy, Andy, Ike, and Granny try their hardest to get him into the Christmas spirit. Meanwhile, Chief has a special gift for him that just might do the trick.