Howard Silk, a lowly cog in the bureaucratic machinery of a Berlin-based UN 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. The only man he can trust is "Prime", Howard's near-identical counterpart from this parallel world.

Howard and his counterpart must work together; Baldwin comes face to face with her past; Emily, from the other side, attempts to make sense of her orders.

Both sides turn to diplomacy to resolve a conflict. Emily obtains a special visa. Howard interrogates a suspect.

Both Howards deepen their investigation of the conspiracy; Quayle meets one of Howard's sources; Clare must decide what to do about Baldwin.

Howard discovers another side of Emily; Howard and Emily search for answers about a mysterious drop site; Aldrich and Quayle seek intel from an old friend.

Aldrich questions a not-too recent passing in the office; Emily, Howard and Shaw follow a lead.

Clare's past is revealed; Quayle suffers through his own birthday party.

The aftermath of the Indigo school discovery takes an emotional toll. Quayle grapples with his wife's new identity.

Howard attempts to thwart the Guest's plans. Howard and Emily chase Kaspar.

A crisis at the O.I. leaves both Howards stranded.