"The Shield" alum Jay Karnes and "Downton Abbey" star Brendan Coyle have signed on to appear in the upcoming second season of "12 Monkeys," Entertainment Weekly reports.

Karnes will play Robert Gale, an FBI agent from the 1940s who suspects a man named James Cole (Aaron Stanford) of committing grisly crimes. Gale also believes that Cole "might not be from this time."

Coyle will debut in the first episode as Dr. Benjamin Kalman, "a former Markridge bioengineer racked with guilt over the deadly virus his team gave birth to." He joins Cole and Ramse (Kirk Acevedo) in their attempt to stop the Army of the 12 Monkeys.

Starring Aaron Stanford (“Nikita,” “X-Men: The Last Stand”), Amanda Schull (“Suits”) and Kirk Acevedo (“Fringe,” “Dawn of the Planet of the Apes”), the series follows a time traveler who arrives in our present to prevent the spread of a deadly plague that will push humanity into a post-apocalyptic future.

“12 Monkeys” will return to SyFy in early 2016.