Captain Janeway is a Klingon warrior complete with holographic cranial ridges when she is critically wounded by a Hirogen participating in a Klingon holodeck program. The Hirogen heals her wounds and she is put back to work in a second, more spectacular program: a town in Nazi-occupied France circa 1944. The Hirogen find Nazism fascinating, and are using the program to experience life in a military bent on conquering the planet. The Hirogen take on the roles of Nazi officers patrolling the town of St. Clare, with Voyager's brainwashed crew as their prey, members of the French Resistance.
Janeway is now Katrine, a French restaurateur and leader of the underground plotting against their Nazi occupiers. She works with bartender (Tuvok), who is loyal to the movement, and a chanteuse and munitions expert (Seven of Nine, whose voice was not dubbed during the songs). Neelix plays a baker who ferries messages and secret codes to the resistance headquarters. He is eventually wounded and transferred to the Klingon program after his recovery. B'Elanna is a heavily pregnant French girl named Brigitte whose affair with a Nazi Captain allows her access to enemy areas (Roxann Dawson actually was pregnant while filming this episode).
The Hirogen enjoy using the Voyager crew in the simulation, because they are more rewarding to hunt down and kill than are holograms. In Sickbay, The Doctor is furious that he must repeatedly save his crewmates from life-threatening wounds sustained as they are hunted in the simulations. He is also distressed that there has already been one Voyager fatality. Harry Kim, who is being forced to expand the holodecks throughout the entire ship, works with The Doctor to regain control of the ship and its crew from the Hirogen.