The 35-year-old actress will reprise the role of Erika Flynn in the season's third episode. The character first appeared in season three after she killed her husband, John Flynn. She attempted to cover up the crime with the help of her assistant, but was convicted of murder and imprisoned. Flynn returned in season four when she offered Patrick Jane (Simon Baker) help on a case from prison. She seduced the sleuth while on furlough and eventually escaped.
The new episode will see Flynn and Jane reunite in Beirut. Jane and Teresa Lisbon (Robin Tunney) have been tasked with taking down an international weapons dealer, and Flynn agrees to help the pair in exchange for a pardon and the chance to return to the U.S.
Baccarin is known for her role as Inara Serra on Firefly, and has also appeared as Nurse Jessica Kivala on Heartland, Anna on V, Isobel Swift on The Good Wife and Jessica Brody on Homeland.
Season seven of The Mentalist premieres this fall on CBS.