10 Most Heartbreaking Doctor Who Moments
4. Donna's Memory Erasure
A comedic duo who stole the hearts of Doctor Who fans across the globe. The friendship between ordinary Donna Noble, played beautifully by Catherine Tate, and David Tennant's 10th Doctor is palpable.
From the start she is loud, opinionated, and wonderfully human. As the series progresses, Donna grows and learns a lot about her own self worth, becoming stronger and stronger from each experience. However, this humanity is her tragic downfall when she absorbs some of the Doctor's regeneration energy, giving her knowledge that her brain cannot contain.
She tries to hide her pain from the Doctor, but he understands what is happening immediately. She begins speaking rapidly as her mind tries to focus with all the knowledge of a Time Lord inside. To save her life, the Doctor wipes her memory as she cries and begs him not to.
When Donna wakes up she doesn't recognise the Doctor and introduces herself. The Doctor gives her a final goodbye as she brushes him off whilst on the phone. This is not only the loss of a friendship but the loss of everything Donna became, and had learnt from her experiences.