When Mac is shot, he finds himself in limbo between life and death and, as he fights for his life, it's up to his team to bring the shooter to justice.
The CSIs are called to a Brooklyn housing project to investigate the murder of a successful businessman who still felt the pull of his old neighborhood.
When a lab tech is murdered in a case that has eerie similarities to a 1950's cold case, the CSIs get a glimpse into what goes on in the shadows of the lab.
Mac comes back to Christine's restaurant to find it packed with people. Meanwhile, Jo visits Sid in the crime lab and finds him playing his newly purchased piano.
Mac brings in a suspect for questioning after they discover cocaine in his apartment. He admits to chasing Greg but tries to convince them that he did not kill him. Meanwhile, Jo finds a new victim in the park.