Burning Falls - Summer Chronicles, #3

Summer's in the midst of a rivalry between the scientifically altered people living on Forsaken Harbor. As things heat up on the island, our heroine and her friends are thrown in the middle of a war that will rip them apart. When Summer discovers those she trusted most are keeping life-altering secrets, she flees the violent harbor for the wild jungle. Realizing Summer's missing, Julian and Gage fight their way through the jungle and come across a mysterious burning waterfall.
Summer's there, but so is someone else .