12 Darkest Star Trek: Voyager Moments Ever

Vidiians. Enough said.

In the first season episode Phage, on an away mission, Neelix gets his lungs taken by a Vidiian and is left to die. Back on Voyager the Doctor provides him with holographic lungs, but they won't last. It's a race against time to get Neelix lungs before he dies.

Janeway is forced to contend with her principles as she has to decide whether to kill a Vidiian to get Neelix's lungs back or let Neelix die. It's a dark moment, as Janeway is clearly grappling with her emotions and principles when faced with the Vidiians responsible. Hearing their story visibly affects her and the audience is left to wonder whether her compassion for these Vidiians will outweigh her feelings for Neelix.

Also, it's a terrifying idea that someone somewhere may one day have the technology to take out organs without operating on the people they are taken from. The Vidiians returned in later episodes to once again provide some dark moments (face stealing anyone?), but the first encounter was the darkest of them all, because nobody even knew the threat existed.