Nature of the Beast

After spending months tracking down his target, Tony (Michael Weatherly, right) is left with the blood of an NCIS agent on his hands and it's up to Gibbs (Mark Harmon, left) to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS. Photo: Sonja Flemming/CBS

After spending months tracking down his target, Tony is left with the blood of an NCIS agent on his hands and it's up to Gibbs to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS. Pictured left to right: Sean Murray, Cote de Pablo, Brian Dietzen and David McCallum Photo: Sonja Flemming/CBS

After spending months tracking down his target, Tony is left with the blood of an NCIS agent on his hands and it's up to Gibbs to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS. Pictured: Guest star Scott Wolf Photo: Sonja Flemming/CBS

After spending months tracking down his target, Tony is left with the blood of an NCIS agent on his hands and it's up to Gibbs to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS. Pictured left to right: Sean Murray, David McCallum and Brian Dietzen

After spending months tracking down his target, Tony is left with the blood of an NCIS agent on his hands and it's up to Gibbs (Mark Harmon, right) to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS.. Also pictured: Rocky Carroll, left Photo: Sonja Flemming/CBS

After spending months tracking down his target, Tony is left with the blood of an NCIS agent on his hands and it's up to Gibbs (Mark Harmon, left) to help him put the pieces of the puzzle together, on the ninth season premiere of NCIS, Tuesday, Sept. 20 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Also Pictured: Guest star Scott Wolf, right Photo: Cliff Lipson/CBS

First look from "Nature of the Beast" featuring Tony and EJ's reunion. Winning caption by Megan K.

First look at Tony and EJ's reunion on NCIS.