Percy Jackson and The Sea of Monsters by Rick Riordan

The book “The Sea of Monsters” is about a demigod who goes to save his friend who has been captured by a cyclops. He gets caught up by meeting his arch enemy for the second time.
He helps his new found friend at school who turns out to be his brother. They go to Camp Half Blood but the tree (which is protecting the camp from minotaurs and other mythical beings.) is dying by getting poisoned. The rest will be revealed as you read on.

By wazyy