When newlyweds Tim and Beryl move into 10 Rillington Place, they are befriended by their older neighbours the Christies. As time passes and their relationship hits a rough patch, Mr Christie's interest and influence over the couple takes a much more sinister turn.

After the strain of Timothy Evans's trial, Christie finds it increasingly difficult to maintain the charade. As his marriage breaks down, he embarks upon a course of action which finally reveals his true nature to the world.