Look sir, an Assassin's Creed glitch! This was spawned during a mission in which you dress up to to kill a target.
"You are left exposed and in need of escape," YouTube user spoon01 wrote. "Well, I tried to escape and look what happened—a full fledged army spawned in to find me."
No one of them thought to look in the haystack. Spoon01 tried to take advantage of the situation by poisoning ten of the guards for an in-game achievement, but he didn't have any poison bombs on him.
Forget the poison bombs. It was probably the fact that
TK421 spoon01 wasn't at his post that gave him away!
Assassin's Creed Revelations GLITCH [YouTube]