"The Man in the Brown Suit" by Agatha Christie is a thrilling mystery about a young woman named Anne Beddingfeld who craves adventure and finds herself caught in a dangerous game after witnessing a strange incident on the London subway. Her journey begins with shady characters like Nadina, a dancer worried about being watched and her precious diamonds, and a mysterious "Colonel", along with a man who falls to his death on the tracks. When a woman is later found murdered, Anne's curiosity sends her off to solve both mysteries that are deeply intertwined with espionage and unexpected connections, that completely changes her life.

The Man in the Brown Suit
By Agatha Christie
A young woman seeking adventure gets more than she bargained for when a subway accident and a mysterious murder pull her into a world of spies, diamonds, and deadly secrets.
Summary
About the AuthorDame Agatha Mary Clarissa Christie, Lady Mallowan, was a British author known for her 66 detective novels and 14 short story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She also wrote the world's longest-running play, the murder mystery The Mousetrap, which has been performed in the West End of London since 1952. A writer during the "Golden Age of Detective Fiction", Christie has been called the "Queen of Crime"—a moniker which is now trademarked by her estate—or the "Queen of Mystery". She also wrote six novels under the pseudonym Mary Westmacott. In 1971, she was made a Dame (DBE) by Queen Elizabeth II for her contributions to literature. Guinness World Records lists Christie as the best-selling fiction writer of all time, her novels having sold more than two billion copies.
Dame Agatha Mary Clarissa Christie, Lady Mallowan, was a British author known for her 66 detective novels and 14 short story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She also wrote the world's longest-running play, the murder mystery The Mousetrap, which has been performed in the West End of London since 1952. A writer during the "Golden Age of Detective Fiction", Christie has been called the "Queen of Crime"—a moniker which is now trademarked by her estate—or the "Queen of Mystery". She also wrote six novels under the pseudonym Mary Westmacott. In 1971, she was made a Dame (DBE) by Queen Elizabeth II for her contributions to literature. Guinness World Records lists Christie as the best-selling fiction writer of all time, her novels having sold more than two billion copies.