Skeleton Crew is the 4th episode of NCIS Season 15 and also the 334th episode of the entire NCIS series.
During a storm that has shut down Washington D.C. and also knocked out power, the NCIS team investigate the kidnapping of a sailor with Torres and Bishop being sent out to sea to track evidence which is connected to the case while Director Vance welcomes NCIS Special Agent Jacqueline Sloane, a forensic psychologist he lobbied to transfer from California to headquarters and on board the ship, Bishop meets a face from her high school days.
- NCIS Special Agent Jacqueline "Jack" Sloane who is also a forensic psychologist is introduced for the first time.
- It is revealed that Vance and Sloane had history together, and that the latter possessed severe scarring on her back from unspecified circumstances. Both would later be revealed in the Season Fifteen finale Date With Destiny (episode).
- It's revealed that Bishop's nickname during her time in high school was "Scarecrow".
|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.|
|Donald Mallard||David McCallum||Chief Medical Examiner for the NCIS Major Case Response Team. Despite being credited, McCallum does not appear in this episode.|
|Clayton Reeves||Duane Henry||Interagency Liaison between MI6 and NCIS. Despite being credited, Henry does not appear in this episode.|
|Guy Ross||Kent Shocknek||ZNN News Anchor.|
|Ottsley||Jill Czarnowski||NCIS Tech.|
|Jacqueline Sloane||Maria Bello||NCIS Special Agent.|
|Thomas Buckner||Trevor Donovan||Navy Commander who went to school with Bishop.|
|Ethan Wynn||Alberto De Diego||Marine First Lieutenant and assault victim as well as the husband/widower of Navy Lieutenant Junior Grade Helen Wynn.|
|Helen Wynn||Sabina Gavrilov||Lieutenant Junior Grade in the United States Navy, the wife of Marine First Lieutenant Ethan Wynn and daughter of Constance Belmont. Uncredited role.|
|Constance Belmont||Gates McFadden||Navy Lieutenant Junior Grade Helen Wynn's mother.|
|Joe Smiddy||Andrew Puente||Navy Petty Officer Third Class.|
|Mitch Greyson||Andrew Asper||Banker and killer.|
|Farrah||Alexis Stier||Party goer.|
|Sarah (Skeleton Crew)||Megan Stier||Party goer.|