VOY S1E5 - The Phage

While exploring a cave, aliens ambush Neelix and steal his lungs. Voyager tracks the thieves down and discovers a new race called the Vidiians. Once a thriving culture, a disease that slowly eats their bodies has turned them into a band of thieves, stealing and grafting organs to survive. Janeway can't get back Neelix's lungs without killing the man who is now using them. Her Federation ethics bar her from passing a death sentence, and she can certainly empathize with their plight, but as his captain, she also owes a duty to Neelix. What can she do?