There were a lot of murders done during that there French revolution, and Ubisoft's latest trailer explains that you'll be investigating some of them as the Assassin (with a capital A) Arno. An assassin solving murders—whatever next. Actually, I know whatever's next, because creative director Alex Amancio divulges that information in the aforementioned video, which details the many activities you'll be able to get up to in Unity's open world historical Paris. In addition to the Assassin's Creed Columbo bits, you can seek out treasure, do co-operative heists, and take part in the revamped Contracts system (now called Paris Stories).
Your homesteady base of operations in Unity is the Cafe Theatre, also known as the 'Cafe Theatre' in English. "This is a hub for all of Arno's Assassin activities, and a home for all your social features", according to Amancio—it's basically the place where you'll train up, and look at all the stuff you've accrued throughout the game.
Unity's system requirements were revealed yesterday, and they're pretty steep.