Doctor Who: 10 Worst Things The Twelfth Doctor Ever Did
5. Leaving Clara Alone In Deep Breath
Regeneration is always a complicated process for the Doctor and it's not uncommon for the Doctor to be a little off their game after regenerating. However, the Doctor is at least used to regeneration, less so for any companions who are with them.
For Clara Oswald this proved to be even more challenging, as the Twelfth Doctor wasn't the easiest Doctor to get on with at the start. Especially after he left her in mortal danger during their first adventure together.
When the Doctor and Clara are investigating a restaurant that's a front for androids that are harvesting humans, the two get separated. Clara ends up trapped in a room with the androids and, rather than try and save her or even offer any words of comfort, the Doctor leaves.
Of course being the Doctor he does come back to save her, but he still did leave her and didn't offer any reassurance that he'd come back. It's little wonder Clara took some time to adjust to Twelve after an experience like that.