Father Tanner treats the sick and injured on a dusty backwater planet. Desperate for supplies, he takes a job to treat a visiting alien official, teaming up with Damien Rogers, an out-of-work smuggler, to get him there. The problem? They're on the wrong side of enemy lines in the middle of a cold war.
Forced to hide their identities, Father Tanner and his team are stumped by the bizarre patient, whose condition steadily worsens. To make matters worse, the alien crew catches onto the ruse, and the missionary is forced to turn to kidnapping. Can they find the diagnosis before their only bargaining chip dies on the operating table?