Seadog is the third episode in NCIS Season 1 and the 3rd episode of the entire NCIS series.
Synopsis
When the body of a Navy Commander washes up on a beach along with the bodies of two drug dealers, the NCIS team investigate and soon discover it might be linked to a potential attack against the United States which if successful could leave the country without any electricity.
Prologue
Act One
Act Two
Act Three

Gibbs after learning from FBI Special Agent Tobias Fornell that the killers they're looking for aren't drug dealers: they're terrorists.
Act Four
Trivia
- It is shown that Abby and Gibbs knows sign language (ASL) for the first time. It is explained that Abby knows ASL due to her parents being deaf but it was never explained how Gibbs knows ASL.
- When in Abby's Lab, Abby first signs, "I have a match." Then Gibbs signs, "You're great." Then She signs, "AK Guns kill " (very rough translation of ASL) This part is somewhat unseen but is translated by Gibbs verbally to, "She just said that the A-K Forty Seven round that killed the Commander came from the same weapon that killed our two drug dealers.". When Tony is surprised that Abby signs, Gibbs signs, "Her parents are deaf." Then he signs to Abby, "Thank you." Then Abby signs, "I have more." Next when Tony is confused who Seadog is, Abby signs, "I don't know." When Gibbs and Tony are in the elevator, Tony asks, "How do you sign, 'I should have known'?", Gibbs roughly signs "I should have known"
Cast
Series Regulars
Name | Portrayed by | Role |
---|---|---|
Leroy Jethro Gibbs | Mark Harmon | An NCIS Special Agent in charge of the main NCIS Major Case Response Team. |
Caitlin Todd | Sasha Alexander | A Secret Service Agent previously assigned to the Presidential Protection Detail on Air Force One and who is now an NCIS Special Agent as well as Tony DiNozzo's partner. |
Anthony DiNozzo Junior | Michael Weatherly | The Senior Agent of the main NCIS Major Case Response Team and also the second-in-command. |
Abigail Sciuto | Pauley Perrette | A Goth who is also the Chief Forensic Scientist for the NCIS Major Case Response Team. |
Donald Mallard | David McCallum | NCIS's Chief Medical Examiner. |
Recurring Cast
Name | Portrayed by | Role |
---|---|---|
Thomas Morrow | Alan Dale | Director of NCIS. |
Charlie (Yankee White) | Gregory Itzin | Director of the Federal Bureau of Investigation. |
Gerald Jackson | Pancho Demmings | Assistant Medical Examiner for NCIS. |
Tobias Fornell | Joe Spano | Agent with the FBI. |
Guest Cast
Name | Portrayed by | Role |
---|---|---|
Kent Fuller | William R. Moses | An agent with the Drug Enforcement Agency. |
Darryl Wilkins | Joe Torry | African-American gang leader. |
Frank Trujillo | Benny Nieves | Gang leader and Wilkins's rival. |
Diane Fontaine | Elena Lyons | Reporter. |
Marcy Carruthers | Merle Dandridge | Agent with the United States Secret Service and one of Kate Todd's friends. |
Bobby Jackson | Sam Sarpong | One of the players that Gibbs confronts in the temporary vacant basketball court. |
Basketball Player | Dempsey Pappion | A man who appears in the episode. |
Dave Simmons | Chris Olivero | A college student. |
Sarah Fuentes | Melissa Lee | Another student at the beach party. |
Seth Shakir | Homie Doroodian | A terrorist. |
Jenny | Jodi Bianca Wise | One of the girls Tony interviews about the boat. |
Nancy | Emilie de Ravin | Jenny's friend. |
Carlos | Miguel A. Gaetan | A man who appears in the episode. Uncredited role. |
Tom Bradstone | Dar Dixon | Captain in the U.S. Army and also an Army CID Officer. |
Linn | Mark Holton | Sergeant in the U.S. Army. |
Office Girl | Julie Berlin | Uncredited role. |