Returning to Earth, and the Powell Estate, the Doctor and Rose pay her mum, Jackie, a visit. They find winter has shown up three months early. The flats are covered in snow and ice, inside and out. They catch Jason Harris, a neighbour from upstairs, running away from the flat. He warns them that four days earlier aliens arrived. They were sensitive to vibrations and took everyone, trapping them in ice somewhere on top of the building. Before he can tell them any more, a snake-like ice creature touches him and turns him to ice.