Infinity Ring: #02 Divide and Conquer

When best friends Dak Smyth and Sera Froste stumble upon the secret of time travel- a hand-held device known as the Infinity Ring- they're swept up in a centuries-long secret war for the fate of mankind. Recruited by the Hystorians, a secret society that dates back to Aristotle, the kids learn that history has gone disastrously off course.