Doctor Who: Every Doctor's Darkest Moment

Forget the acid baths and chloroforming Shockeye to death, the Sixth Doctor throttling Peri in The Twin Dilemma is truly his darkest moment.

While the Sixth Doctor immediately feels remorse for strangling his companion, it's hard to escape how sinister an action this is. Especially as the brutal assault takes place not long after her new friend saved her life, then completely changed his face.

The darkness of the moment feels like a cheap way to establish that Colin Baker is a very different Doctor from Peter Davison. Especially as producer John Nathan-Turner and Colin Baker discussed embracing the Doctor's darker and more alien side in the Sixth Doctor era. 

If anyone had turned off during Peter Davison's tenure, it's hard to imagine them jumping on board for a snarling, technicolour dreamcoated Doctor who tries to murder his companions. It's one extreme to another.