It looks like Prince Harry's ex-girlfriend Cressida Bonas has finally made her onstage acting debut. Over the weekend at the Hay-on-Wye Festival, the blonde beauty appeared in a production of "There's a Monster in the Lake."

According to E! News, Bonas took on a minor role in the Tallulah Brown-directed play but reviews revealed that the socialite is quite talented and may have stolen the show.

The director of the production, Lily Ashley, actually had no idea that the new cast member was Prince Harry's ex-girlfriend when she landed her the role of wolf.

The showing was presented at the How the Light Gets in Festival which is actually an alternative part of the Hay Festival.

Organizers of the festival only had one day's notice before learning that Cressida Bonas would appear on stage as part of the cast.

However, now that the news is out, it is clear that the level of secrecy surrounding the production will be harder to hide when "There's a Monster in the Lake" begins its regularly scheduled shows at the Rosemary Branch theatre in London later this month.

Several media outlets reported that the play was performed in a large tent on the grounds of a converted chapel in front of around 30 people.

Just last month, it was announced that Cressida Bonas would join Cara Delevingne and Daisy Lowe in Harvey Weinstein's new movie, "Tulip Fever."

She is set to appear on the big screen opposite Dame Judi Dench, Matthew Morrison, Christoph Waltz and Zach Galifianakis in the Justin Chadwick-directed drama.