World explorer Augustus Skinner has died! Now, his three teen grandsons have inherited the big, old Skinner Mansion and its contents. But Grandpa Skinner also left them a big surprise... The Skinner Boys are now Guardians of the Lost Secrets... a collection of artefacts across the world that possess incredible powers. Grandpa Skinner also appointed a fourth Guardian, their feisty teenage cousin, Tara.

As the anonymous Guardians of these artefacts, Tara and the boys must dedicate their lives to protecting them against the forces that would use their powers for evil and endanger the planet.