A quiet town is hit by a supernatural event that leaves everyone in a certain part of it unconscious, and all the women of childbearing age are found to be suddenly and inexplicably pregnant. As news spreads and tensions simmer, it is up to psychotherapist Dr Susannah Zellaby to help support those affected, while local detective DCI Paul Haynes is given the tasked of maintaining order.

Three years after the blackout. The children are entering the second phase of their development. Susannah notices changes in their behaviour and makes a terrifying discovery. Her worst fears are realised when a forgotten mother emerges.