The team investigates the death of a lieutenant, which appears to be suicide; Nate joins Kensi in the field.
Horatio goes to New York to work with his counterparts on a murder investigation. Guest star Gary Sinise.
When a successful real-estate agent is murdered, the police suspect he may have been the victim of foul play or of his association with low-life James "The Tooth" Fusco (Jon Polito).