When a decorated Marine corporal is killed in Central Park, Mac and Danny must question the members of the platoon who knew him best and saw him last. During Fleet Week, an annual New York tradition showcasing military pride and achievement, the city is awash with servicemen taking a break from their duties. The discovery of a dead Marine in what is traditionally a week of celebration hits particularly close to home for Mac, a former Marine, as he sees a young version of himself in the victim. Meanwhile, the team unites on one case when the victim of a car fire is someone they all knew. Vanessa Ferlito reprises her role as Det. Aiden Burn. After being fired by Mac for tampering with evidence, Aiden returns as the team needs crucial evidence to finally catch a serial rapist, her last case which caused her dismissal. Scenes from this episode were filmed on location at the Intrepid Sea, Air and Space Museum on the Hudson River in New York City.