Disclaimer: Doctor Who, nor the 'idea' nicked from Phillip Pullmans HDM are mine.
Spoilers for Doomsday, in case you missed what I said before.
Once a year, Rose Tyler finds herself facing a blank white wall, where her whole world fell apart.
Once a year, she detaches herself from this world- from this Universe and in her thoughts, she flies.
Once a year, Rose will be by that wall, her cheek pressed against the smooth white surface, a hand splayed out beside it. Tears fall, her heart breaks in two, and her world will come crashing down around her again. An hour, only an hour, before she pulls away, ready for another year.
And once- just once, a year, the Doctor does the same.
fin