Tommy attempts to handle the insanity of his father while defending Colleen's new lifestyle to Janet. At the firehouse, Sean and Mike the Probie unknowingly launch a full blown wager among the crew.

When Tommy discovers a secret that Janet is keeping from him, he must come to terms with the possible consequences. At the firehouse, Chief Reilly preps the boys for their new female replacement. With the help of Franco and Sean, Tommy tracks down the man responsible for Billy's death.

While Tommy attempts to make reason of the chaos in his life, he continues to defy death while pulling dangerous stunts on the job. Lou admits his infidelity to his wife and receives an unexpected surprise. When tragedy strikes his family, Tommy must come to the rescue of his father.

The hockey game rematch between the NYPD and the FDNY is right around the corner and Tommy must figure out a plan to save himself from being pummeled by the cops who have it out for him. Tommy's relationship with Sheila is discovered by the guys and they must adhere to tradition to handle it in their own way. When Tommy is visited by his demons during a fire, Franco comes to his aid... with devastating results.

Franco's addiction to painkillers has driven him to a support group to get help with his problem. A young boy clings to life after Tommy saves him from a fire. Jerry is introduced to his gay son's life partner.

Jerry forces the crew to attend a birthday party that his son is throwing for his boyfriend. Meanwhile, Tommy makes a move on Mariel after she tells him she might not be his half sister after all. Franco asks Laura to move in with him while Sheila tries to make Tommy jealous by showing off her new girlfriend.