Ubisoft has teased a mysterious new section of Assassin's Creed: Unity which appears to be set during World War 2.

The new trailer below, titled "Time Anomaly", shows the player transported to the rooftops of Paris in the middle of an air raid.

You can climb the Eiffel Tower and even take on enemy planes with a machine gun.

"Assassin, watch out," a voice-over states, "the French Revolution simulation is collapsing. I don't know what time period you'll end up in."

You're still playing as the avatar of French Revolution hero Arno Dorian during this section, through some kind of glitch in the Animus software used to recreate Unity's virtual Paris.

It sounds like the glitch is something to do with the game's overall meta-story - which has moved on to the point where evil games developer Abstergo Entertainment is now letting the general public play with their Animus technology from the comfort of their own home.

An earlier leak showed off gameplay footage of an as-yet unrevealed Rift Mode, where you could play as different Assassins through history on challenge maps. It's unclear if this new feature is related: