Ilan Srulovicz

Threat of Extinction. Threat of Extinction. More refugees pour into the Mutant Underground, but the group faces a threat when they discover one of them is a spy working for Sentinel Services.

A retired SEAL -- who tracked people impersonating military personnel -- is murdered; Brody finds that LaSalle is uncharacteristically unenthusiastic about Christmas.

Tess acquires a Kryptonian box that once belonged to Lionel Luthor (former series star JOHN GLOVER). When Clark accidentally activates the box, he's transported to a parallel universe where Lionel found Clark in the cornfields instead of the Kents. In this universe, Clark Luthor is a murderer and Lois is engaged to Oliver – and both of them hate Clark. Clark must be careful not to tip off Lionel that he's not his son while trying to figure out how to get back to Earth where the monster Clark Luthor was transported in his place. Executive producer Kelly Souders makes her directorial debut.