10 Darkest Endings In Doctor Who

For a good portion of his run, the Third Doctor was stranded on then present-day Earth, and found himself assisting UNIT, a military force dedicated to repelling hostile alien invasions. He would often come into conflict with Brigadier Lethbridge-Stewart over the army man’s heavy-handed methods, and the downer ending of this serial underlines their differing philosophies.

UNIT and the Doctor are called in when a nuclear power station reports sudden power drains, and soon discover that the forerunners of humanity on Earth, the Silurians, are living in the cave system under the station. The Doctor does his best to broker peace between the two races, but hostile human and Silurian elements scupper those plans and force him to put the Silurians back into suspended animation, hoping that one day they can be revived and peace talks can begin again.

But just as he is leaving the power station, the Brigadier gives the order to destroy the Silurian base under pressure from his superiors, committing genocide against all of the innocents still down there. The Doctor is outraged at this act of violence and drives off in anger and shame, having failed to stop the human race from indulging their worst impulses.