The Sittaford Mystery

S2 E4: Among the guests at a Dartmoor hotel, a séance starts out as an amusing diversion to pass the time on a snowy evening but then takes a sinister turn. Supernatural events point to danger to Trevelyan, an infamous local staying at the hotel. Meanwhile, six miles away at Sittaford House, Miss Marple finds a not-so-supernatural death threat naming the same man. With snow piling up and blocking the roads, can anyone reach him in time?