'Bridgerton' star Nicola Coughlan shared a major Easter egg from the 1st episode that hints at the big reveal in the season finale

• "Bridgerton" star Nicola Coughlan revealed a major Easter egg about her character's secret.
• According to Coughlan, the hint occurs in the very first scene of the steamy period drama.
• Warning: Major spoilers ahead for season one of "Bridgerton."

If you pay close enough attention, the identity of Lady Whistledown is given away in the very first scene of "Bridgerton," according to star Nicola Coughlan.

On Saturday, Coughlan asked her Twitter followers if they'd noticed the "massive Easter egg" about her character Penelope Featherington, who was revealed to be gossip columnist Lady Whistledown at the end of the series.

—Nicola Coughlan (@nicolacoughlan) February 20, 2021

Several fans theorized that the clue had something to do with a bee, or the fact that the Featheringtons were the first family shown on-screen, but Coughlan revealed that it had nothing to do with either theory.

"When I filmed Penelope's first scene I chose a prop, a massive massive feather," Coughlan wrote in a follow-up tweet.

She also confirmed a fan's theory that the feather was meant to represent a quill - and hint at Penelope's secret occupation as Lady Whistledown.

—Nicola Coughlan (@nicolacoughlan) February 20, 2021

—Nicola Coughlan (@nicolacoughlan) February 20, 2021

But Penelope's giant feather in the show's first scene isn't the only hint about her huge secret that viewers get.

Whistledown repeatedly writes about the secrets of the Featheringtons (including some things that only a member of the family would know) and Whistledown's coachmen wear the same colors as the Featheringtons' servants.

Golda Rosheuvel, who played Queen Charlotte on "Bridgerton," revealed that cast members were given scripts with fake endings in order to ensure that Lady Whistledown's identity remained a secret.

"We never got the right endings in the scripts, so none of the cast really knew," she explained during a recent episode of "The Netflix Afterparty."

"Bridgerton" is based on a bestselling series of books by romance writer Julia Quinn. And while the first season of the Netflix show sticks pretty close to the events of the first book, it does incorporate storylines from later in the series - including Whistledown's unmasking, which happens in the fourth book, "Romancing Mister Bridgerton."

According to Rosheuvel, cast members were left in the dark about Whistledown's identity unless they'd read Quinn's series.

"If they hadn't read the books, none of the cast knew," Rosheuvel said.

Netflix renewed "Bridgerton" for a second season at the end of January, and production is reportedly set to begin in the spring.