Romancing Mr. Bridgerton is the fourth book in Julia Quinn's Bridgerton series. It tells the story of Penelope Featherington, a wallflower who has been secretly in love with her best friend's brother, Colin Bridgerton, for years. When a scandalous gossip column threatens to expose Penelope's deepest secret, Colin becomes determined to uncover the identity of the mysterious Lady Whistledown. As they embark on this quest together, they discover a love that has been right in front of them all along. With its delightful humor and heartfelt romance, Romancing Mr. Bridgerton is a beloved Regency historical romance.