I'm not sure exactly as I haven't read it in detail. But generally, it might be about some mysterious events or adventures related to the Raven's Gate. It could involve a journey of discovery, with characters facing various challenges.
Another important character is a female warrior. She is strong and independent. She plays a crucial role in battles and often challenges the traditional gender roles in the world of the graphic novel. Her skills and courage are essential in the various quests and challenges that the characters face in the story.
The complex plot makes it a classic. There are so many twists and turns. Just when you think you know who the murderer is, Agatha Christie throws in another clue that changes everything.
The main setting is, of course, the Orient Express. It's a luxurious train, and the compartments and corridors add to the sense of mystery and confinement for the murder mystery.