Before Rose and after the Time War. This time is one of the darkest in the Doctor's long life. It is a time where the Doctor is without hope and alone. Utterly alone. He doesn't have a clue what his future holds, nor does he care. He might not even have one if he doesn't change his self-destructive ways.

Yaz doesn't know why she keeps doing this to herself. All she knows is that she can't stop. No one ever said loving a time-traveling, immortal alien would be easy. Is the Doctor worth the pain?