Callis is joining the cast as Dr. Grant, a former Eureka resident whose unexpected homecoming is cause for alarm, says the Hollywood Reporter.
Upon his return, Grant will woo Allison (Salli Richardson-Whitfield), effectively ruffling Jack’s (Colin Ferguson) feathers.
‘Eureka’s Season 4 premieres July 9.
Since ‘Battlestar’ signed off, Callis has guest-starred on ‘Numb3rs,’ where he played a creepy cult leader. He next will appear on ABC’s ‘FlashForward,’ which resumes its freshman season on March 18.