Starz unveiled the first full trailer for “Counterpart” starring J.K. Simmons, which will premiere on January 21 at 8pm.

“Thirty years ago during the Cold War, there was an experiment. Something went wrong, they opened up a passage,” the trailer explains. “When you go through this door, you come out the other side, identical to ours.”

The thriller follows Simmon’s Howard Silk, a lowly cog in the bureaucratic machinery of a Berlin-based United Nations spy agency. When he discovers his organization safeguards the secret of a crossing into a parallel dimension, he is thrust into a shadow world of intrigue, danger, and double cross… where the only man he can trust is his near-identical counterpart from this parallel world. The show explores themes of identity, fate, lost love, and poses the question, “What if our lives could have been different?”

“Counterpart” also features Olivia Williams, Harry Lloyd, Nicholas Pinnock, Nazanin Boniadi, Sara Serraiocco, and Ulrich Thomsen. Created and written by Justin Marks (“The Jungle Book”), the series is executive produced by Marks, Gary Gilbert (“La La Land”), Jordan Horowitz (“La La Land”), Morten Tyldum (“The Imitation Game”), Keith Redmon (“The Revenant”), Bard Dorros (“Spotlight”), and Amy Berg.