Ed Sheeran performed Saturday night in Las Vegas, home of the Killers, so naturally he added “Mr. Brightside” to the setlist. As an added bonus, Brandon Flowers also joined in on the performance.

“There’s this one person I want to bring out. He’s from Vegas,” Sheeran — dressed as Chucky for the pre-Halloween concert at Allegiant Stadium — told the crowd. “We’re gonna the song that is essentially like my country’s national anthem,” a nod to how “Mr. Brightside” was recently named the most streamed song in U.K. history.

After performing the Hot Fuss classic, Flowers stuck around to help Sheeran run through his own “Castle on the Hill.” (The surprise collaboration more than made up for the fact that Saturday’s show was postponed at the last minute six weeks ago due to technical issues.)

The Vegas gig marked the final North American date on Sheeran’s +–=÷x (a.k.a. Mathematics) Tour, which has previously featured surprise guests like Eminem, Busted, Shawn Mendes and more, as well as surprise stops at school recitals, Lego stores and Nashville karaoke bars (where, coincidentally, Sheeran also sang “Mr. Brightside.”)