When the charred bodies of two men who had been robbing a Chinatown bank are found, the entire team investigates the crime, which leads them to Doris, the missing infant of the bank's manager. The team realises that Joanna Cho assisted with the robbery out of fear for her daughter's life. Mac and Stella finally manage to track down the third robber, only to find him lying in a pool of blood, with a trail of bloody baby handprints leading away from the body.

Danny and Mac investigate after a briefcase belonging to Luke Sutton is found left in the NYMEX with a bloody note inside. Their investigation into Sutton's activities lead them to Nick Lawson, whom Sutton had been investigating for illegal trades, but who swears he had nothing to do with his disappearance. Stella and Flack investigate the death of Trina Rolston, a young pregnant women who fell to her death from the roof of a church. With Hawkes help, Stella realises that the body was thrown off the roof to mask the true cause of death. The detectives soon realise that their two cases are connected.

A young John Doe, nicknamed 'Slick', is found lying across the rails of an underground subway. At first, he appears to have died from third-rail electrocution, but an autopsy suggests that he may have met his end by other means of electrocution. Meanwhile, Leo Whitefield is found shot dead at close range in a gallery he owns, with no sign of break in or theft, and a construction worker turns up with a fatal injury to the head.

Mac, Aiden and Flack investigate when Elaine Curtis is found dead at a dog competition, a knitting needle sticking out of her chest, and no shortage of suspects ranging from judges to trainers to contestants. Stella and Danny investigate the death of bicycle messenger Michael Starling, but the crime scene may have been anywhere along his route.

Three drug dealers set to stand trial are found dead in separate places. They were all trying to get rid of witnesses in their crime, but it looks like someone got them first.

Mac informs an ex-con that he served time for a crime he didn't commit, and Lindsay tells Danny "it's time" for the first CSI baby to be born.

Mac is on the hunt for a sniper who is using nitroglycerin in his bullets to explode on impact, and the prime suspect was once a missing boy from one of Mac's old cases.