The detectives investigate a murder at a grocery store that is also connected to the death of a young man with the tattoo "Tanglewood" on his back. A third case involves a woman who was killed in a hit-and-run auto accident.

Stella and Danny are heading into the world of cuddle parties: non-sexual events were adults learn to touch and hug each other. Meanwhile, Mac, Hawkes, and Flack investigate the death of a hated plastic surgeon found covered with lye with thousands of eyewitnesses during rush hour at Grand Central Station. While Mac and Stella assist Aiden in a rape case, after she breaks an evidence seal, Mac must come to terms with Aiden's action and work up the nerve to fire her.

The CSI's handle to puzzling cases; Carensa is a young Suicide Girl who at 17, wanted a change of scenery and to become a Suicide girl, at 18 she gets her wish only to lose her life. Chopper, a rising street basketball star, a homeless man trying to change his life for the better is killed and leaves a painful trail of blood which leaves Mac to figure out where and how he died.