A United Nations investigator crosses paths with a pair of psychic sisters on his way to Trollenberg observatory in the Swiss Alps, which has been plagued by a series of mountaineer disappearances that may be related to a radioactive cloud at the mountain's south face.
Colonel Mortimer returns to his family after a long spell in India to find his young son in bed ill, and tormented by a wailing voice... but is it in the boy's imagination or not?
A half-hour anthology series.
