The Long Chron — Adam Oster

When a stolen relic sends them back in time, con artists Chelle and Griff try to return in the same way they arrived: scamming, scheming, and swindling. But following the rules of the Scammer's Bible might not be enough for these two unlikely heroes as they find themselves in the midst of a battle for not only a medieval town's freedom, but also the integrity of all of history. Griff and Chelle must use all their wits to find out the secrets of the mysterious Wizard and the history of the puzzling Reprobian Sphere that brought them to the past or risk death at the hands of all who support The Wizard's evil plans.