The genes of Isis - Justin Newland

Akasha is a precocious girl, born into a world where oceans circulate in the sky waters. She dreams of releasing the Surge, the next evolutionary step for an embryonic human race. But it's dormant, trapped inside every human. Horque is a Solarii, a tribe of angels who've manifested in human form and settled in ancient Egypt. Desperate to return home, they must first undo the devastation caused by the Helios, another tribe of angels who came to Earth to deliver the Surge and instead left humanity on the brink of extinction and sired a race of interspecies monsters: the hybrids. When Akasha foretells the falling of the sky waters and falls in love with Horque, her life becomes an instrument for apocalyptic change.