A/N: Tag to 4x13 Journey's End.
For His Whole Life
He looks down at her still form as she sleeps off the effects of having her memory wiped clean. His heart aches with every rise and fall of her chest. With every breath she takes he is reminded that when she wakes, she will not know him. There's nothing worse that he can think of.
Everything in him screams that he should go back in time and fix what happened to her. Everything in him screams that he should find some way to protect her that he couldn't think of the first time around. He shouldn't be leaving her like this. It's not right.
He takes a deep breath and slowly exhales.
And screw the consequences! This is Donna and she doesn't deserve this. She deserves access to the memories of all the things she has done with him on the TARDIS. She deserves to remember. She is his one in five billion; he wants her to know that.
But, no.
He can't.
To change time to save her would be wrong. It could be disastrous and he can't risk it. She has saved him on many occasions in many different ways, but he cannot do the same for her this time.
He had to erase her memories to save her life. He had no choice.
In his heart, he knows he'll carry the guilt around with him for years to come (for his whole life). He will keep an eye on her from afar and make sure she's okay – but even if she is okay, and he's certain that she will be, he will feel guilty for what she has lost and can't recall.
He also knows in his heart that while he'll miss her like crazy and feel her loss every day, he has done the right thing.
fin.