Foo Fighters may be the mystery band on this year’s Glastonbury lineup; Dave Grohl seemingly dropped a hint in a letter to fans.

On Tuesday (6/6) the Foos frontman posted a handwritten note on Twitter thanking fans for attending the band’s latest run of shows. “It feels good to see you, churning up these emotions together,” he said. “See you soon.”

Eagle-eyed fans have made the link between “churning up”—certainly not a common expression—and The ChurnUps, an unknown band scheduled to play Glastonbury’s Pyramid Stage on Friday, 6/23.

Foo Fighters headlined Glastonbury in 2017. They were booked to play in 2015 but had to pull out days before the performance when Grohl broke his leg and dislocated his ankle during a show in Gothenburg, Sweden, where he fell 12 feet off the stage (remarkably, he finished the show with his leg in a cast).

If their slot for this year is confirmed, they'll join acts including Elton John, Arctic Monkeys, Caroline Polacheck and Guns N' Roses on the bill.