"It doesn't have to work forever, sweetie," she said softly, almost sadly. It didn't. For her this was the last time, and even for him, it was finite. Long, but not forever. Still, 'it doesn't have' to was noncommittal enough. It was clear this was an end. He just wasn't accepting it. But he would. Eventually, he would. And he still had all that time of theirs ahead of him. All that time to love her.

And perhaps that was the nicest thing she could have done for him, to die in front of a version of him that didn't yet care about her.

But he was the Doctor. He didn't have to care... to try. Death itself was a foe.