At a séance, Sir Alington, a venerable expert of the mental condition, is pestered by Mrs. Eversleigh about the importance of the sixth sense. Soon, a young man named Dermot is drawn in and tells them both about the sixth sense he experiences, a red signal that spells danger. He is about to tell them of the last time he saw the red signal when he stops himself. The last time he had the signal was earlier that very evening. But how could there be danger at a simple gathering of old friends? Will the evening bring forth whatever impending danger that Dermot senses?