Heaven's Hill

Ruth Pritchard's childhood friend, Oliver Dacey, works for GCHQ. When he starts hearing fanciful messages broadcast on shortwave radio, he discovers an ability to travel in time. He involves Ruth and inevitably, the authorities take an interest in them both. At the heart of the mystery is Oliver's mother, Dee, who once directed them in games which bear an uncanny resemblance to the broadcast messages.

Ruth and Oliver travel back to 1965, and they find themselves to be the characters from their childhood games. It appears that Oliver's mother is still directing them. It is a glamorous, but often confusing and frightening world.