Danny causes waves in the department when he investigates a closed case, the suicide of a firefighter, at the insistence of the man's 12-year-old son. Meanwhile, Jamie saves a baby from a burning building but worries it will jeopardize his undercover work when he is billed a hero in the press.

Danny and Jackie investigate the suspicious death of a high-rolling investor who sustained injuries in a fight, yet his hands are unmarked by trauma. Also, Frank places Jamie under house arrest when the Sanfinos put out a hit on "Jimmy Riordan".