6x5 - Star Trek: Hidden Frontier

To better understand the tetrahedrons operation, an interrogation of the Orion Syndicate pirate Mason is conducted. When he reveals the location of another tetrahedron key, a mission is set up to retrieve it, with his help. But one of the officers will not return, and the others will be left reeling at the loss of one of their own. Shelby encounters a few ghosts of her own, when assigned to assist a Romulan fleet make the necessary adjustments to traverse the Patch, and runs into her former lover, Captain Mackenzie Calhoun.