A man dressed as a knight is found dead in Central Park, while blocks away a man, bound to a bed, is discovered dead in a penthouse suite. When Sid Hammerback discovers fingerprints on both men's eyelids left by the same person, the CSIs realize the cases are connected. The prints are from a woman not in CODIS, leaving the CSIs to wonder why the same woman plunged an ice pick into Bobby Smith's neck and drove a lance through Derek Kirson's chest. Sid discovers another connection: both men were terminally ill, Bob with leukemia and Derek with an inoperable brain tumor. Hawkes analyzes a blonde hair found on Bob's body and determines it was bleached and the woman it belongs to was using marijuana. Calls placed to Bob's hotel room lead the CSIs to Isabella Cooksey, but she claims she was simply selling Bob's condo for him and refuses to give up her DNA.
Mac rushes to Peyton Driscoll's side after a man in a silver Mercedes SUV shoves her and steals a body from the ME's truck. Danny is able to get a license plate imprint off a dumpster the SUV hit while fleeing the scene, and the CSIs bring in the owner, Christopher Beaufield, the son of a city councilman. He denies stealing the body, and during the interrogation Mac and Peyton receive a page: the body has turned up in the Hudson River. They go to retrieve it and are shocked when the man's eyes pop open. He's rushed to the hospital where he's declared brain dead. A silk hair from a goat that Danny discovers leads him and Mac to Dr. Quinn Brookman, who runs a genetic testing lab. Quinn IDs their victim as Court Peterson, one of his lab techs. Quinn denies knowing anything about Court's odd fate.
Peyton and Mac test Court's blood and discover an odd amalgamation of chemicals in it. The pair realizes Court was put into hibernation, which mimicked death. They arrest Quinn and Christopher, who together with Court were trying to find a way to induce hibernation in humans. An unusual flower found on Derek's body leads the CSIs to a greenhouse owned by Dr. Henry Croft. Croft recognizes both victims: they were in a support group for terminally ill young people. He tells them Isabella is part of the group as well, and when they spot medical marijuana in his greenhouse, he tells them of a fourth member: Jenny Parker. The CSIs race to her apartment, but it's too late: Jenny, dressed as Marilyn Monroe, is dead in her bed. Isabella tells the sad story: the four made a pact to die together. Jenny killed the two men before killing herself, but Isabella couldn't go through with it. Stella returns to the lab and tells Mac she wants to take a PCR DNA test to determine her HIV status quicker.