Percy Jackson and the mortal instruments crossover

Percy's pov

I was walking with Annabeth on a beach when I got an iris message from Chiron. He gave me a location and told me and Annabeth to reach there in 10 minutes. When we reached there we saw Chiron , piper , Jason , hazel , frank and Leo waiting for us
Chiron said " okay that's everyone" "now I called you all here to brief you on your next mission a few of my friends are dealing with some problems and I hope you can help them, now go in that room they are waiting for u" and Percy I looked at Chiron and he whispered be nice
So when I entered the room I saw a blond boy with too much gel in his hair a redhead girl and (I'm guessing) there friends
There were seven grim faces staring at us....