# Mark Harmon's Original Gibbs Replacement Returns to NCIS After 6 Years

> Sean Harmon returns as FBI agent Casey Bloom in NCIS: Origins after 6 years.
- Title: Mark Harmon's Original Gibbs Replacement Returns to NCIS…
- Summary: Sean Harmon returns as FBI agent Casey Bloom in NCIS: Origins after 6 years. Sean Harmon reprises his role as FBI agent Casey Bloom in NCIS: Origins Season…
- Keywords: ncis, sean harmon, mark harmon, casey bloom, fbi, ncis origins, sean harmon return, gibbs character, ncis season 3, ncis episode 2, entertainment, culture
- Source: CBR — https://cbr.com/ncis-origins-season-3-episode-2-sean-harmon-fbi-character
- Author: Hannah Postlethwait
- Published: 2026-10-16T03:35:35+00:00
- Read time: 1 min
- Topics: ncis, sean harmon, mark harmon, casey bloom, fbi, ncis origins, sean harmon return, gibbs character, ncis season 3, ncis episode 2, entertainment, culture
## Sean Harmon Returns to NCIS
Sean Harmon reprises his role as FBI agent Casey Bloom in NCIS: Origins Season 3, Episode 2.
## Mark Harmon's Exit from NCIS
Mark Harmon exited NCIS after 19 seasons in 2026, his character last appearing in Season 19.
## Casey Bloom's Role
Bloom partners with FBI Agent Josephine Swanson on the Woodrow Browne murder investigation.
## Bloom's Background
Bloom has been undercover with a biker gang for the last year, calling them 'beautiful people' carrying pain.
## Bloom's Character Insight
Bloom says he likes to think there's a little Keanu in all of us, referencing Johnny Utah from Point Break.
## Sean Harmon's Previous Role
Sean Harmon previously played young Gibbs in NCIS Season 18, Episode 2.
## Why Sean Harmon Didn't Reprise Young Gibbs
Sean Harmon focused on executive producing NCIS: Origins instead of reprise younger Gibbs.
## Bloom's Future in NCIS
NCIS Special Agent-in-Charge Cliff Wheeler confirms Casey Bloom will return in future episodes.
## Key takeaway

Sean Harmon reprises his role as FBI agent Casey Bloom in NCIS: Origins Season 3, Episode 2, following Mark Harmon's exit from NCIS after 19 seasons.