Taylor Swift turned part of her Eras Tour show in Poland into a duet!

At the 14-time Grammy winner’s third and final Eras Tour show in Warsaw on Saturday, Aug. 3, Swift surprised the sold-out crowd by performing a mashup of The Tortured Poets Department track “The Black Dog” and folklore breakup song “exile” featuring Bon Iver.

During Swift’s mashup on piano as part of the secret songs portion of the show, her fans stepped in to sing Bon Iver singer Justin Vernon’s “exile” verse and back-and-forth parts since he wasn’t in attendance.

This is the fourth time Swift, 34, has performed “exile” as a surprise song during the Eras Tour, as she previously sang it in Los Angeles in August 2023, Australia in February and Scotland in June.

In a video captured by a fan, the crowd could be heard screaming as she began “exile” before they started singing the lyrics to Vernon’s first verse.

“I can see you standing, honey / With his arms around your body / Laughin’, but the joke’s not funny at all,” the fans sang with Swift. “And it took you five whole minutes / To pack us up and leave me with it / Holdin’ all this love out here in the hall.”

Then, as Swift sang her parts during the chorus, bridge and outro, the Swifties loudly harmonized with Vernon’s back-and-forth parts.

For the guitar portion of the secret songs segment, Swift played a mashup of Fearless track “Today Was a Fairytale” and Lover track “I Think He Knows.” At one point, she said, “Every day is a fairytale in Poland!”

When she began her Warsaw leg on Thursday night, the concert marked Swift’s first-ever headlining concert in Poland, after she skipped over the country for her last five tours.

During her second performance in the country on Friday, she wowed the crowd with Polish phrases, telling the stadium “warszawa, witajcie na Eras Tour” (“welcome to the Eras Tour”), “kocham was” (“I love you”), “dziękjię” (“thank you”) and “wszystko dobrze” (which loosely translates to an “everything’s fine?” or “all good?”), among other phrases.

The show comes on the heels of a couple whirlwind weeks for the “Cruel Summer” singer, who just toured through Germany, playing seven shows in three different cities and debuting live performances of songs in her expansive discography along the way.

In Munich, the last city before heading to Poland, she even made headlines for the thousands of fans that gathered on a hillside outside of the concert venue to watch the three-and-a-half-hour show from afar.

“We’ve got people in a park outside the stadium, thousands of people listening from out there!” Swift told the German crowd. “I just feel so incredibly welcomed, and we’re gonna spend all night trying to make it up to you.”