When the world is in danger, when royal families need protection, when supervillains steal from orphans and little old ladies, the Spy Sisters are trained to save the day!

Meet the spies. Their real names are classified:

Sister #1, code name, Kay-7. She is thirteen, and it's her job to protect her younger sisters—and the whole world. That's a lot of pressure for an eighth grader who has a big history test on Wednesday.

Sister #2, code name, Scarlett (or Scar for short). She's ten and hates jumping out of airplanes. Villains fear her left-handed yellow boomerang.

Sister #2, code name, Mia. She's in first grade. Her favorite color is purple. She's a language expert, even though she's only six.

When their parents are kidnapped, the Spy Sisters accept a super-secret mission from Dr. Nobody to track down and defeat the notorious Snake Ten-Fangs. With the help of their family's bionic dog, Scarlett's flying carpet, and Kay-7's smartphone named Brad, the Spy Sisters must travel from India to Alaska to the Galapagos Islands.

Can they save their parents—and the world? It's what the Spy Sisters do.