Doctor Who: 10 Times The Doctor Lost
4. When He Realised He Can't Bend Time To His Will
The notion of fixed points in time - and whether or not the Doctor can change or interfere with established incidents and events - has been a major theme throughout NuWho, and David Tennant's final episodes had these ideas at the forefront.
This Doctor in particular liked to flip the bird at time itself, and believed he had the power to change or mess with absolutely anything he desired, despite it being clear he should leave certain things alone. When you mess with time, time can mess back, and the Doctor certainly found that out at the end of The Waters Of Mars.
In this episode, the Doctor lands on Mars, where he meets Adelaide Brooke, a woman whose death will inspire her granddaughter to lead humanity through space. The Doctor has actually encountered Adelaide on the day of her death, and throughout the episode, he wrestles with the issue of whether or not he should save her. Can he alter this fixed point in time, one that will lead to important events further down the line?
Initially, the Doctor decides to leave Adelaide to die, but soon has a change of heart, bringing her back to Earth instead. Here, Adelaide ridicules him for his decision and furiously states that he should have left her on Mars, to which the Doctor responds... no. He is the Time Lord Victorious, and he can do whatever the hell he wants.
The Doctor's ego is bursting off the screen in this moment and he clearly believes that he has the power to bend time to his own will, but he quickly comes crashing back down to Earth when Adelaide enters her home and commits suicide, ensuring her death remains a fixed point.
Realising he's gone too far, the Doctor crashes to his knees, clearly in regret over his recent actions. We've covered plenty of physical losses on this list so far, but this ideological, philosophical defeat crushed the Time Lord just as much as any other.