Blood in the Water is the first episode of NCIS Season 19 as well as the 415th episode of the entire NCIS series.
As the NCIS team searches for Gibbs after wreckage from his boat is discovered, they find out he was tracking a serial killer with journalist Marcie Warren who wrote an exposé on him.
- Despite being credited, David McCallum doesn't appear in this episode.
- This is also the first episode of the entire NCIS series to have Rocky Carroll and David McCallum sharing the "With" credit.
|Leroy Jethro Gibbs||Mark Harmon||Ex Special Agent Assigned to NCIS Major Case Response team. (Indefinitely Suspended)|
|Timothy McGee||Sean Murray||Senior Agent for the NCIS Major Case Response Team. Currently in charge.|
|Nicholas Torres||Wilmer Valderrama||Special Agent for the NCIS Major Case Response Team.|
|Jessica Knight||Katrina Law||NCIS Special Agent.|
|James Palmer||Brian Dietzen||Chief Medical Examiner for the Major Case Response Team.|
|Kasie Hines||Diona Reasonover||NCIS Forensic Specialist.|
|Donald Mallard||David McCallum||NCIS Historian. (credit only)|
|Leon Vance||Rocky Carroll||NCIS Director.|
|Marcie Warren||Pam Dawber||Journalist.|
|Eleanor Bishop||Emily Wickersham||Former NCIS Special Agent. Archive footage. Uncredited role.|
|Thelma McKeever||Katherine Cortez|
|Virgil McKeever||Dave Florek|
|Randall Sledge||Travis Hammer||Faux County Deputy.|
|Regina Unger||Terryn Westbrook||County Deputy.|
|Marta Jimenez||Yenniffer Behrens|
|Brent Hollister||Colin Land||NCIS Special Agent.|