Narrowly beating that passionate speech at the Doctor from Dark Water, is the moment that also severed Clara's connection to the TARDIS. The Twelfth Doctor's ruthlessness sees him abandon Clara on the Moon, forcing her to make an impossible choice - save the Earth or the alien living within the Moon? For Clara this has huge ramifications for their relationship. Clara's rant against the Doctor was her best performance to date. The moment she tells him to shut up, we know something is very wrong. Forcing back the tears she screams at him that he went too far. He nearly made her make the wrong choice and she argues clearly that he should have been just as invested in saving the Earth; he walks and breathes the same air as her. She tells him to go far away, knowing this man will bring out the worst in her. Arguably that was one of the most sensible decisions she ever made. Sadly for Clara she came back and while she experienced more thrills and adventure, it came at the cost of her own life in the end.