The Doctor faces an ethical dilemma over a medical hologram's data.
Voyager takes aboard a dying, insect-like alien that attaches itself to B'Elanna Torres, linking their bodies. To separate them, the Doctor creates a hologram of Crell Moset, a famous Cardassian expert in alien biology. A Bajoran crewman then reveals that Moset carried out cruel experiments on Bajorans during the occupation, and Torres refuses to be treated by him.
Janeway overrules her, and the operation goes ahead in the holodeck while the alien's own people hold Voyager in a tractor beam. Chakotay restores power so the surgery can finish, and the alien is returned to its kind. Torres is furious with Janeway, and the Doctor, troubled that he has used knowledge gained through atrocities, has the Moset program deleted. The fifth-season episode is a story about medical ethics and whether knowledge gained through cruelty can ever be used, and it draws on the Bajoran occupation from Deep Space Nine.