What does Stephenie Meyer have up her sleeve?

That’s the question many fans of the Twilight author are asking after a mysterious countdown clock was posted to her website, CNN reports.

Visitors to Meyers’ site are greeted with a clock counting down to Monday morning. There’s no other information about what might lie in store for fans, so they’ve taken to social media to speculate.

The most popular guess seems to be that Meyer is planning to announce a publication date for Midnight Sun, a version of Twilight told from the character Edward’s point of view. (For the uninitiated, Twilight is told from the perspective of Bella, a 17-year-old girl who falls in love with Edward, a sparkly vampire.)

“If that countdown isn’t for midnight sun i'll fucking riot, stephenie,” warned one Twitter user.

“I swear to GOD if [stephenie] meyer releases midnight sun after a goddamn DECADE i will lose my mind and INSTANTLY regress into my twilight phase and there is nothing anyone can do about it,” wrote another.

Some fans of Meyer think she might be preparing to announce a sequel to her 2008 novel, The Host.

“Fingers crossed for the host sequel,” wrote one Twitter user, evidently a fan of the science fiction novel.

Not everyone saw it the same way, though. “Stephenie Meyer please do not break my fragile heart..just tell us...don’t leave us guessing,” tweeted one fan. “We want Midnight Sun...not a sequel to The Host.”

Watch this space Monday for news of Meyer’s announcement and/or Twitter riots.

Michael Schaub is a Texas-based journalist and regular contributor to NPR.