"Wherever this cocaine has travelled, it hasn't gone alone. Death has been its attendant. Death in a remarkably violent and inelegant form." The Seventh Doctor, Chris and Roz, arrive at the Quadrant, a troubled council block in Thatcher's Britain. There's a new drug on the streets, a drug that's killing to a plan. Somehow, the very ordinary people of the Quadrant are involved. And so, amidst the growing chaos, a bizarre trio moves into number 43. The year is 1987: a dead drug dealer has risen from the grave, and an ancient weapon is concealed beneath human tragedy. But the Doctor soon discovers that the things people do for their children can be every bit as deadly as any alien menace - as he uncovers the link between a special child, an obsessive woman, and a desperate bargain made one dark Christmas Eve.