I solemnly swear I am up to no good
A magical promise that lets you see the Marauder’s Map like it’s your job. Fred and George told Harry Potter this because they’re the worst and they like to mess with people.
I said the magic words and saw my crush’s whole gang. Now I know where to find them.
I solemnly swear I am up to no good. Now I know where my teacher is hiding. Time to prank her.
I used the phrase and saw the whole school plotting against me. I’m going to get revenge.