¿Por qué no le preguntan a Evans?

During a quiet round of golf, Bobby Jones, son of Marchbolt's vicar, inadvertently deflects the ball off a cliff. As he searches for her, he discovers a dying man and deduces that the mist caused him to fall. Moments before he dies, the man whispers a mysterious question: "Why don't they ask Evans?" In an attempt to identify the victim, once it is concluded that the death was accidental, they find a photo of a woman in his pocket. Bobby begins to wonder that what seemed like an accident might actually be a murder. He will then start, together with his friend Frances Derwent, a great fan of solving mysteries, an investigation to discover the truth.