Gabriel Stone Series by Shannon Duffy

Gabriel Stone is a twelve-year-old boy still reeling from the unsolved disappearance of his mother. With a dad who’s hard to relate to, and mounting pressures at school, Gabriel lets off steam by hiking in the place where his mother was last seen. There, Gabe and friends find a crystal that proves not only beautiful, but magical beyond their wildest dreams. Only, magic and beauty come with a price: in order to return home, they must save the dying world of Valta.

Gabriel Stone is back from Valta, but the adventure is just beginning! His friend Tahlita is trapped in Willow Creek with no memory of Valta. Gabe, Piper, and Brent are determined to reunite Tahlita with her father. Yet even as they do, Prince Oliver arrives asking for their help. Menacing forces known as the Solarians have kidnapped the Empress and Princess and are threatening the lives of humans everywhere... moreGabriel Stone is back from Valta, but the adventure is just beginning! His friend Tahlita is trapped in Willow Creek with no memory of Valta. Gabe, Piper, and Brent are determined to reunite Tahlita with her father. Yet even as they do, Prince Oliver arrives asking for their help. Menacing forces known as the Solarians have kidnapped the Empress and Princess and are threatening the lives of humans everywhere. Along with talking tracker monkey, Finley, the friends battle vampire mermaids and a living, blood-filled lake in their quest to save the Empress and Princess. Even with cool new powers, Gabe discovers their strongest weapon is their friendship as they battle the Solarians and rescue a cursed white witch—who may be the only one who can save Valta. less