10 Biggest WTF Moments From Star Trek: Voyager

In the Voyager episode Nothing Human, Lieutenant Torres became fused with an alien lifeform resembling a facehugger, which paralysed her and slowly sucked out her body's energy to keep itself alive.

Unable to detach the alien from B'Elanna, The Doctor decided to create a holographic consultant to assist with his research. He chose a notable Cardassian doctor, Crell Moset, as the basis for the program.

The two holograms started to make progress learning about the alien. We got to know Moset, and were made to empathise with him when B'Elanna made bigoted comments against Cardassians, but eventually a Bajoran engineer named Tabor revealed that Dr. Moset was actually an infamous mass murderer from the Cardassian occupation of Bajor, who conducted twisted experiments on Bajoran people that killed hundreds (including members of Tabor's family). The crew was forced to deal with the moral implications of benefitting from the research that took the lives of so many Bajorans. B'Elanna flat-out refused to be treated by him when she learned the truth, but The Doctor went against her wishes, detaching the alien with the help of the Moset hologram.

At first, after his past was revealed, the hologram argued that those evil experiments were not in the Starfleet database, and therefore not part of his program, but, when he began defending the atrocities he committed during the occupation, The Doctor was forced to delete him.