Books like The Man in the Brown Suit by Agatha Christie

The story follows Anne Beddingfeld, a young English orphan who seeks adventure in London. While waiting for the tube at Hyde Park Corner, she witnesses a man collapse onto the live tracks and die instantly. A doctor examines him, declares him dead, and leaves a cryptic note—"17.1 22 Kilmorden Castle"—in Anne’s hand. The next day, newspapers report the murder of a celebrated ballet dancer, brutally strangled at Kilmorden Castle, and the disappearance of a fortune in diamonds. When Anne is aboard the luxury liner named Kilmorden Castle, strangers attack her cabin, attempting to strangle her. With each clue, Anne realizes that the danger extends far beyond London, possibly reaching Africa. Throughout the suspenseful journey, she must outwit a faceless killer called "The Colonel" who is determined to eliminate her and seize the hidden treasure.

First publish date: 1924