Mac, Stella, Sheldon and Lindsay investigate the death of a museum curator murdered in the wing her wealthy family donated and the crime's only witness refuses to talk.

Mac becomes particularly protective of the only witness in his murder investigation, a young boy found in shock at the exhibit, who after seeing the grizzly crime, confuses the events at the museum with a comic book he was reading at the time. The team works to discover if the motive was money, given the curator's wealth, or if the witness has something to do with it when the CSIs find he has ties to the victim.

Meanwhile, Danny and Det. Flack are called to a construction site where a man is found dead with a mouth full of foam sealant, which leads them to an extreme golf association with members who play in the streets of the city's five boroughs.