Paula Hawkin's debut novel follows an unemployed alcoholic called Rachel, who spends her days riding the same commuter train every day and concocts a perfect life for a couple she always comes across during her travels.

However, her life is turned upside down when she suddenly becomes involved in their real-life drama.

The book has since become the fastest-selling adult novel in U.S. history, after shifting more than two million units since it was published in January (15).

The Help filmmaker Tate Taylor is onboard to direct, while Men, Women and Children screenwriter Erin Cressida Wilson is adapting the script for DreamWorks Studios.