We don't have a lot to go on, but a couple of fan tweets plus a cryptic set list points to the fact that Harry somehow was able to keep this gig top secret from the world.
Something that is basically impossible, especially if you know the fandom and their investigative skills.
"HARRY STYLES LIVE IN CONCERT - THURS JUNE 29 - Holmes Chapel Comprehensive School" reads one poster on Twitter.
Not only was this Harry's school, but it's the same school that Nell Jones, victim of the Manchester attack, attended.
If you see his set list, you'll notice that he replaced "From The Dining Table" with One Direction's song, "Long Way Down."
BRB, CRYING 5EVA!
One fan praised Harry for performing.
"@Harry_Styles you're so brave for doing the Holmes Chapel concert. I can't be more proud of you. Sending all my love to you and your family."
This is a call to the fandom to get digging! We want more deets on this!