Maria Bello has joined the cast of CBS’ long-running drama NCIS as a new series regular opposite Mark Harmon for the upcoming 15th season. Bello is coming off a co-starring role opposite Billy Bob Thornton on the first season of the Amazon drama series Goliath. It is unclear whether she will appear in the second season, but she no longer is a series regular as NCIS has her in first position.

Bello will play an NCIS agent who was commissioned as a second lieutenant in the Army and served two tours in Afghanistan. After joining NCIS, she built her reputation as the agency’s premier forensic psychologist. Unlike the other agents, she can second-guess and challenge Gibbs (Harmon), so there will be friction but also mutual respect. She is a positive force, mischievous and at times acerbic. Her character will be introduced in the season’s fourth episode.

“We have always been big fans of Maria Bello’s work and are excited to be introducing her as an agent who not only has a distinct talent but also a unique relationship with Gibbs,” said NCIS executive producers/co-showrunner George Schenck and Frank Cardea.

Bello, who plays Thornton’s ex-wife Michelle McBride on Amazon legal drama Goliath and recently was cast opposite Kyle MacLachlan and Josh Wiggins in upcoming YA drama Glo, from writer/director Keith Behrman, and in MGM/Likely Story/FilmWave’s upcoming YA romantic drama Every Day. She’s repped by UTA, John Carrabino Management and attorney Bob Myman.

The 15th season of NCIS premieres September 26.