The song they play at the beginning of the episode is "The Army Song," also known as "The Caisson Song." Not the right music for "Fleet Week," when they should play "Anchors Aweigh."
Danny Messer (Carmine Giovinazzo) and Mac Taylor (Gary Sinise) investigate the death of a Marine. In reality, this case would have been investigated by the NCIS (Naval Crime Investigative Service) team.
While Mac Taylor (Gary Sinise) and Dr. Sid Hammerback (Robert Joy) are examining the marine's body, the chest moves as the "deceased" marine is breathing.
About halfway through the episode, when Danny is updating Mac on the Marine case in Mac's office, Danny says, "The vic[tim] was playing the shell game in Times Square at 9 p.m. and was found dead in Central Park at midnight." However, the Marine died around midnight, he was not found at that time. His body was discovered by the boy around 11 a.m. (Mac says in the beginning that he had been dead for approximately 11 hours).