When best friends Dak Smyth and Sera Froste stumble upon the key to time travel - a handheld device known as the Infinity Ring - they're swept up in a centuries-old war for the fate of humankind. Recruited by a secret society named the Hystorians, the kids learn that history has gone disastrously off course. Now it's up to Dak, Sera, and young Hystorian Riq to travel back in time to fix the Great Breaks.