Zachary "Zack" Nichols is a fictional character, portrayed by Jeff Goldblum, featured in the NBC-USA Network series Law & Order: Criminal Intent.
Nichols is a police detective with the NYPD Major Case Squad. He was introduced in the series' eighth season to replace Mike Logan (Chris Noth). During that season he and his partner Megan Wheeler (Julianne Nicholson) were featured in half the episodes shown, alternating with Robert Goren (Vincent D'Onofrio) and Alexandra Eames (Kathryn Erbe); the next year, during the show's ninth season, he and his new partner Serena Stevens (Saffron Burrows) were the only detectives featured. Neither Nichols nor Stevens returned for the tenth and final season of Criminal Intent, however, their characters were not specifically written out or addressed in any way during that season.
Detective Nichols was once partnered with Captain Danny Ross (Eric Bogosian) in Anti-Crime. However, after September 11, 2001, Nichols left the police force for seven years. Ross remarked that during this period, his only clue to Nichols' whereabouts was a postcard from Cleveland.