The year is 1948. Reverend Bernard Paltoquet and his friend Dr Robbie MacTavish go on a tour of Europe and encounter a mystery in a Bergen forest. Why are the ghosts of two children haunting a fir tree? The following Christmas, that very tree turns up in the church hall and the ghosts of the children with it. It seems they cannot rest until their murderer has been brought to justice and only the psychic Robbie can help, even though he doesn't speak a word of Norwegian! It seems an impossible task, but Robbie is determined to help them, despite all the obstacles in his way.