On a stormy night, Xiao Chi, a gray fledgling with no clan mark or flight feathers, falls from the sky and crashes into the royal nest of the Divine Eagle clan. Heavy as stone, she cannot ride the wind and fly like the Divine Eagles. Yet with a single call of “Mama,” she is adopted by Cang Ling, the queen. The Great Elder, Jin Lie, exploits an ancient prophecy to brand Xiao Chi a calamity destined to destroy Skycliff. Secretly, he steals the Mountain-Guarding Thunderstone and manipulates the Thunder Crown, causing thousands of eagle nests to plummet. To protect her mother and older siblings, Xiao Chi plunges into the sea of thunder, awakening the Thunderbird bloodline that vanished a thousand years ago. With lightning and wind, she holds up the entire Skycliff. When the truth is finally revealed, she earns the respect of her clan and comes to understand that a true family is never defined by bloodline, status, or the ability to fly.