Gwen records a piece to camera detailing what has been happening over the previous few days as she believes that the World as they know it is coming to an end. Gwen also asks and answers a question of her own, why has she never asked Jack anything about the Doctor. He has referred to him numerous times in the past but she has never asked about him. She now realises that there are some times when he doesn't arrive to save the day and that the reason is that "sometimes, he must look at this World and turn away in shame."
Since it has been revealed that Britain received a visit from the 456 in 1965 and covered it up, the Prime Minister has become impotent in that all proceedings have now been taken over by an American General on behalf of the United Nations. A plan is put into action which sees the development of a cover story for the children that will be selected for handover to the 456 which will be that that they will be given innoculations against the freezing and chanting that they have been experiencing.
The plan moves into the action phase and yellow buses accompanied by troops see children being removed from school and bused off with parents and teachers powerless to do anything. While this is going on, a representative from UNIT is sent in to find out from the 456 what they actually use the children for. Do they need them to survive? It seems not as the 456 answer, "No, they make chemicals.....they make us feel....good." It seems to the 456, the children are a recreational drug, and the 456 have become addicted!
It seems that in order to gain trust from the general public with regard to the innoculations, Frobisher must be called on again to be a servant of his country. His children will also be chosen and will take the innoculations live on television. But Frobisher knows the truth and cannot bear the thought of what lies in store for his children. He signs out a gun and goes home. The last thing we see is him ordering his wife and daughters into an upstairs bedroom. The last thing we hear are gunshots.
Meanwhile Jack has been taken away and thrown in jail but not before telling Gwen that "They're after the children. Ianto has a niece and nephew. Save them." He then contemplates the fact the there seems to be nothing he can do. Gwen flies back to Carfidd with Rhys and they go to tell Ianto's sister that he is dead. Then the troops find that some children are missing from school they turn up at the estate where Ianto's sister lives and start taking children from the houses. The parents start to fight back, but they are no match for the troops. Gwen, Rhys and the others take the children out of the back while the fighting goes on in the streets in order to try and hide them.
After being persuaded that she is not necessarily being given all the facts and that her orders shouldn't be followed, Johnson busts Jack out of jail and also grabs the technology guy that has been studying the 456 since their last visit in 1965.
Back at the hub, he and Jack eventually figure out a way to combat the 456, they must use the children and the 456 frequency carrier wave that they were controlling the children with, against them. In another sacrifice by Jack, he uses his own grandson as a conduit for the signal and needs to amplify it up so much that he risks killing him but he opts to do it anyway. As the signal is fed through Jack's grandson and out to all the other chilren on the planet, the children start to scream and in a burst of flame, the 456 are gone. The trouble is that Jack's grandson collapses into his mother's arms.