Two Steps Back is the 22nd episode of NCIS Season 15 and also the 352nd episode of the entire NCIS series.
This episode also marks the final appearance of both Pauley Perrette (Abby Sciuto) and Duane Henry (Clayton Reeves).
When evidence reveals a member of the NCIS team is a hitman's latest target, the team must search through old case files to determine who is seeking vengeance while they mourn the unexpected loss of a close friend.
- It's revealed that Reeves died defending Abby.
- Following the case, Abby officially resigns from NCIS.
|Leroy Jethro Gibbs||Mark Harmon||Special Agent in charge of the NCIS Major Case Response Team.|
|Abigail Sciuto||Pauley Perrette||Chief Forensic Specialist for the NCIS Major Case Response Team.|
|Timothy McGee||Sean Murray||Senior Special Agent and second-in command of the NCIS Major Case Response Team.|
|Nicholas Torres||Wilmer Valderrama||Special Agent for the NCIS Major Case Response Team.|
|Eleanor Bishop||Emily Wickersham||Special Agent for the NCIS Major Case Response Team.|
|James Palmer||Brian Dietzen||Assistant Medical Examiner for the NCIS Major Case Response Team.|
|Leon Vance||Rocky Carroll||Director of NCIS.|
|Jacqueline Sloane||Maria Bello||NCIS Special Agent.|
|Donald Mallard||David McCallum||Chief Medical Examiner for the NCIS Major Case Response Team.|
|Clayton Reeves||Duane Henry||Interagency Liaison between MI6 and NCIS.|
|Robert King||Peter Jason||Biological weapons specialist and terrorist captured through the efforts of Abby Sciuto in 2009. Real name Tom Reese|
|Terry Spooner||Eddie Jemison||A businessman who hired a hitman to stop Abby Sciuto from testifying against him back in 2006.|
|Alejandro Rivera||Marco Sanchez||Brother of Paloma Reynosa who is currently serving a life sentence.|
|Grace Confalone||Laura San Giacomo||Successor to Dr. Cyril Taft as Gibbs's therapist.|
|Tobias Fornell||Joe Spano||Former FBI agent who is now a private investigator.|
|Caitlin Todd||Sasha Alexander||Former NCIS Special Agent who was murdered by rogue Mossad officer Ari Haswari. Archive footage. Uncredited role.|
|Michael Franks||Muse Watson||Former NIS agent. Archive footage. Uncredited role.|
|Anthony DiNozzo Junior||Michael Weatherly||Former NCIS Special Agent. Archive footage. Uncredited role.|
|Kent Marshall||Mark Engelhardt||Former army specialist and hitman.|
|Brendan Denridge||Joe Sabatino||Night-shift guard.|
|Silver||Isaac Stephen Montgomery||Prison Guard.|
|Nurse (Two Steps Back)||Monica Lawson|