The Blue Geranium

On this occasion, the Tuesday Night Club mystery lovers hear a story about a woman who was warned by a psychic of evil and danger in her house. On a full moon, she must watch for the signs: blue primrose means caution, blue hollyhock means danger, and blue geranium means death! It's not long before the woman claims to see blue geraniums in the house. Is Miss Marple up to dealing with the supernatural?