You're an Ottoman assassin. You've got a den. You need to freaking well defend it, son. You're going to need some crossbows on the rooves and some instantly appearable barricades. What the Sam Hell's going to happen if you haven't? Not much point being an Ottoman assassin if you're dead, is there?
Check out this stuff in action in the latest Assassin's Creed: Revelations trailer after the break. The game's out for PS3 and 360 on November 15 in the US and November 18 in Europe.