Indie rock band Peter Bjorn and John will perform at Dillo Day on May 28, Mayfest officials announced via a campus-wide scavenger hunt Monday.

Fifteen letters were hidden in boxes wrapped like presents around campus. Mayfest invited students to search for the letters and return them to the rock, where Mayfest members strung the letters along a clothesline at The Rock, gradually spelling out the band’s name.

The final clue came in around ??:?? Monday.

The Swedish band completes Mayfest’s lineup announcement, which features nighttime headliner B.o.B, daytime headliner The New Porgnographers and hip-hop duo Chiddy Bang.