Walking down the aisle at her wedding, Donna Noble is transported to the TARDIS.  The Doctor tries to get her back to her wedding, even though she is rude and abrasive, and just barely misses the wedding.  Meanwhile, he discovers that she is full of Huon, something that the Time Lords eradicated long ago.  They discover an ancient race that is trying to revive their ship by creating new Huon particles in Donna and in so doing will destroy the Earth.