Simplify the following text for a Grade 7 native English-speaking person.
Original: There he discovers Percy Jackson , a half-blood , and alerts Mr. Brunner the Latin teacher , who really is Chiron , Camp Half-Blood 's activities director .
Simplified: There he discovers Percy Jackson , a half-blood , and alerts Mr. Brunner the Latin teacher , who turns out to be Chiron , Camp Half-Blood 's activities director .