When Dale Barge is found dead in a playground, Nikki and Jack face the alarming prospect that his murder is linked to the disappearance of a little girl, Lizzie.
Social worker Louise fears the worst when Daniel Garvey, the estranged stepfather of teenager Kevin, whose case she managed, is found dead in his car.
Psychic powers and stone beasts run riot in old Pompeii, but can Donna dare The Doctor to change established history?