Imagine the Cold War, except instead of two foes covertly fighting on either side of Berlin’s physical wall, they’re separated by a metaphysical wall. That’s the premise of Starz’s upcoming drama Counterpart, which dropped its first official trailer on Thursday.

The show, which stars J.K. Simmons in two roles, for reasons that’ll make sense soon, is about a man named Howard Silk (Simmons) who has been toiling away for years as part of a secretive but boring bureaucracy in Berlin. Suddenly, he’s brought into the agency’s inner circle as a cooler, darker version of Howard Silk from a parallel universe comes forward with news of a cross-dimensional assassination plot. Turns out, both Silks work for agencies that monitor and guard either side of a parallel dimension that sprung up 30 years ago.

And, well, those two realities don’t quite get along, as things haven’t gone exactly the same way for each dimension in those three decades since the split.

The “parallel dimension” bit sounds like a classic science fiction gimmick at first, but it’s really the framework for a neat twist on the spy/espionage genre.

Here’s the official synopsis for the show, via Starz:

Counterpart is about a mysterious world hidden beneath the surface of our everyday existence. Howard Silk (J.K. Simmons) is a lowly cog in the bureaucratic machinery of a Berlin-based United Nations spy agency. When Howard discovers that 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 and lost love, posing the eternal question, ‘What if our lives could have been different?’

Counterpart, which stars J.K. Simmons, Game of Thrones’s Harry Lloyd, Olivia Williams, and J.K. Simmons, premieres on January 21, 2018, at 8 p.m. Eastern on Starz.