The Mentalist has cast English actress Polly Walker in a major recurring role.
Walker - most recently seen in BBC drama Prisoners' Wives - will play a new FBI agent, TVLine reports.
Her character Alexa Shultz is a quick-witted and feisty senior operative and will make her debut in the CBS drama's fifth season.
State of Play, Rome and Caprica are among Walker's previous television credits, while her film roles include 1992's Patriot Games, 2010's Clash of the Titans and 2012's John Carter.
The Mentalist - which stars Simon Baker as a former phoney psychic-turned-criminal investigator - will move to a new Sunday night slot for its fifth season.
The series will return to CBS in the US on September 30. In the UK, the series airs on Channel 5.
> Prisoners' Wives second series confirmed
Watch an interview with The Mentalist star Owain Yeoman (Rigsby) below: