Nicola Coughlan as Penelope Featherington on season three, episode six of "Bridgerton."Liam Daniel/NetflixMultiple characters discover Lady Whistledown's real identity in "Bridgerton" season three, part two.This happened in "Romancing Mister Bridgerton," the book it's based on — but Netflix does it better.Here's how the plot differs from the book and why the show's version is an improvement.Warning: Major spoilers ahead for "Bridgerton" season three, part two, and the book "Romancing Mister Bridgerton."Penelope Featherington's secret identity as Lady Whistledown is finally revealed in part two of "Bridgerton" season three.Since season one, Penelope (Nicola Coughlan) has secretly published a gossip column about London's high society under the pseudonym Lady Whistledown.In seasons two and three, Penelope's double life creates trouble for her as Queen Charlotte (Golda Rosheuvel) and Eloise Bridgerton (Claudia Jessie) begin hunting for Lady Whistledown's real identity.A similar storyline occurs in "Romancing Mister Bridgerton," the Julia Quinn book this season is based on."Bridgerton," one of Netflix's most-watched series, has already made plenty of book changes (both good and bad), including revealing Penelope as Lady Whistledown to the audience way back in season one.