"Murder on the Orient Express" is a classic detective novel written by Agatha Christie, featuring her famous detective character, Hercule Poirot. The novel was first published in 1934 and is considered one of Christie's greatest works.

The story is set on the luxurious Orient Express train traveling from Istanbul to Calais. The train is full of passengers from different backgrounds and nationalities, including wealthy businessman Samuel Ratchett. During the night, Ratchett is brutally murdered in his cabin, and the train is stranded due to a snowdrift, leaving all the passengers trapped on board.

Poirot, who happens to be on the same train, is approached by Ratchett's concerned friend, who believes that someone is out to get him. However, Poirot is too late to prevent the murder and takes it upon himself to solve the case. He interviews all the passengers and examines the evidence carefully to find the culprit. As he delves deeper into the investigation, Poirot uncovers some shocking secrets about Ratchett's past, which lead him to suspect that anyone on the train could be the murderer.

The novel is a masterpiece of detective fiction, with Christie's trademark twists and turns that keep the reader engaged until the very end. It is also known for its unique solution to the crime, which has become one of the most famous in the genre.

Overall, "Murder on the Orient Express" is a gripping and entertaining read, perfect for fans of classic detective stories. It also explores themes of justice, revenge, and morality, making it a thought-provoking novel that remains relevant today. Christie's expert writing and Poirot's brilliant deductive skills make this book a timeless classic that continues to captivate readers all around the world.