The night that Rea and her twin brother turn twelve, everything changes for them. They live in Darjeeling, India, near a tea plantation, and when Rohan goes missing on their 12th birthday. But he isn't in Darjeeling; he is held captive in the land beyond the banyan tree, Astranthia. It is up to Rea and her best friend Leela to find and save Rohan and maybe find out the secrets Amma has kept hidden from her.