A woman named Sandra chases her husband, Jason, down a balcony at the Powell Estates, begging him to stop, to listen, as he heads away under the spell. Rose and Mickey pop their heads out of Jackie's flat, and Sandra complains, "He won't listen! He's just walking, he won't stop walking!" She notes the strange light, confused, and continues to follow him, her voice rising. Down on the ground are lots more normal people, staring and hypnotized in the light, heading somewhere. At UNIT, Llewellyn wonders why only certain people are being affected; Alex informs the group that they're getting reports from all over the country. In the stree,t a woman walks along, pleading with her daughters and her son; her husband. Begs them to stop and come home. They ignore her and continue to walk, as the crowd swells. All around them are frantic unaffected people trying to stop the horde.
A policeman walkies that they're heading for the highest buildings -- "Anything with stairs; anything with steps" -- and Llewellyn and Blake, inside the Tower of London, watch as the affected staff head all the way up, onto the roof. Outside, the policeman realizes what's going to happen, watching from the street: "There's hundreds of them...Oh, God. They've gone right to the edge. They're gonna jump." Llewellyn pleads with Sally to stop, as she walks closer and closer to the edge. "It's Danny Llewellyn. Daniel Llewellyn. Sally, just concentrate," he pleads, getting hysterical. All over the world, Paris and Rome. London at dawn. It's beautiful and eerie, shots of a third of the world standing on buildings and ruins, waiting. Standing on the very edge. Two billion people ready to jump. So this is Christmas. "Surrender, or they will die..." says Llewellyn, breathlessly.
Up on the roof with Sandra and Jason, the whole world holding its breath, Mickey asks Rose what the hell they can do. "Nothing," Rose says helpfully. "There's no one to save us. Not anymore." The Doctor would be so proud.
Llewellyn and Blake come back downstairs; Alex has figured out the beginning weft of a pattern: "All these people tend to be father and son, mother and daughter. Brothers and sisters...family groups, but not husbands and wives." Llewellyn puts it together and gasps, drawing Alex and Harriet's attention. "It's Guinevere One. Have you got medical records on file for all your staff?" Alex gives them to him, and Llewellyn accesses the records. Off to the side, Harriet asks about Torchwood. "Still working on it. Bear in mind, they have just lost a third of their staff," says the Major, and she asks if they have "what we need." They do. "Well, tell them to hurry up." Llewellyn shows them Sally's med records: "blood group A+." Who else walked out? Luke Parsons, Jeffrey Baxter...all A+. Major Blake: "How many people in the world are A+?" Um, guessing about one-third? Llewellyn explains the worst part: they got the blood from Guinevere One. "Maps and music and samples...wheat seeds, and water, and...and blood. A+. The Sycorax have got a vial of A+." Which somehow, Harriet sees, gives them control over the blood. Harriet decides on her last-ditch defense, taking the Major upstairs.