A new trailer for Assassin's Creed Unity shows some kind of spacetime disturbance taking Arno from the time of guillotines to era of Nazi occupation. A late-2013 Ubisoft survey about the future of Assassin's Creed had floated the idea of an AC game letting players explore a city through different era. That's one of the few things that hadn't appeared as a feature for this year's AC games yet, but today's trailer suggests that may indeed be an element of Unity after all.