In order to use Donna Noble’s biology as a catalyst to awaken the children of the omnivorous Empress of the Racnoss, who are hibernating at the center of the Earth, Lance, a worker at a security company that was formerly owned by Torchwood, secretly and gradually poisons his fiancée, secretary, with Huon particles over the course of six months. Donna appears inside the TARDIS as a result of the particles’ interaction. Despite their best efforts, the Tenth Doctor is unable to attend Donna’s wedding. The Empress feeds Lance to her children by dumping him down a shaft beneath the River Thames that leads straight to her children, and she wakes them up with the Huon particles within Donna and Lance. The Empress uses her spaceship, shaped like a Christmas star, to attack humanity. The doctor asks him to locate a different universe where the Racnoss can live in peace. The Doctor floods the shaft with Thames water using explosive baubles after the Empress rejects the proposal. When the Empress’s energy runs out, the army uses tanks and artillery to kill her. When the Doctor asks Donna to accompany him on his trip, she says he needs someone to control his temper.