KC and Marshall are helping out with the baby tigers at the National Zoo when they meet a new friend, Sunwoo from China. Sunwoo's father is lending the zoo a precious jewel called the Tiger's Eye to raise money for endangered tigers. But during the zoo's big party, the lights suddenly go out. And when they're turned back on, the jewel is missing Who stole the Tiger's Eye? And how did someone sneak it out of a room with no windows and a guarded door?