Karnes, 52 and Coyle will join the previously cast Michael Hogan for the science fiction mystery drama, reported Entertainment Weekly.
Karnes, will recur as a savvy FBI agent in the 1940s named Robert Gale, who believes a series of grisly murders may have something to do with a man named James Cole (Aaron Stanford), an outsider who Gale suspects might not be from this time, reported Entertainment Weekly.
Meanwhile, Coyle, 51, will first appear in the season premiere as Dr Benjamin Kalman, a former Markridge bio-engineer racked with guilt over the deadly virus his team gave birth to.