A sudden blast buffeted the three of them, knocking the Doctors and Rose down onto Mars's rocky surface. The Doctor turned around, his gaze sweeping past the burning wreckage as he looked for Rose and Ten-and-a-Half. It wasn't until after he had made sure his companions were safe and unharmed that he was able to taken in the horror that lay before them.
All that death and destruction, because he couldn't do anything to stop it.
"Isn't there anyway we can help them?" Rose asked.
No not because he couldn't do anything to stop it, but because he wasn't allowed to do anything.
"It's a fixed point in time," Ten-and-a-Half reminded her. "Any attempt to save them would have terrible consequences. If we're lucky all that would happen…"
They were bound by the whims of time. But he was a Time Lord, the last of the Time Lords. Why shouldn't he save anyone he wanted to? Time should bend to his whims, bow to his commands, not the other way around. He would be the Time Lord Victorious –
"Doctor Ten!" Rose said sharply, tugging on his hand. "I said, Ten-and-a-Half and I decided, if we can't save them, at least we can stay here on Mars until… Well, no one should have to die alone."
Startled, the Doctor finally looked at Rose, really looked at her. Silent tears rolled down her cheeks, belied by her determined expression. He didn't even need to see Ten-and-a-Half to know how he looked, grim and resolute. His double would know the arrogant turn Ten's thoughts had taken, and would do everything necessary to stop him.
Which was absolutely nothing. Because in the face of such a quiet form of tear-stained bravery what could the Doctor do but go along?
"Yes, we definitely should stay."