The Heir of Voldemort (Harry Potter and Percy Jackson)

When Percy Jackson and Annabeth Chase meet Harry Potter, Ron Weasly and Hermione Granger. Who brought them together and why? Were they wizard or Demi-God. Why don't you read and find out. Rights go to Rick Riordan and J.K. Rowling.
WRITTEN BEFORE CURSED CHILD CAME OUT
Disclaimer: I wrote this in 6th grade. The grammar is not as good as it could be, but I have too much going on right now to edit it.