More details in the comments

She then texted my head of year, who in turn said that I should go to our common room, wear a party hat, and get a picture taken. Luckily I had no afternoon lesson, so I just left after my midday class.

My head of year teacher’ll be hunting for me tomorrow.

Tbh that's funny as all hell and you need to wear the party hat.

Ugh. Apparently they were looking for me at lunch time, but I had long gone. I’m afraid for tomorrow though. Ik they’ll hunt me down

I kinda need to know how the fish hunt ends

Well. You’ll find out tomorrow for sure