"Well, I'm sorry. I didn't expect any problem being in your company." says Orerreth. "The object is a crystal" whispers, answering Stulgar's question. "Slightly smaller than a fist, similar to those wizards use to hold their spells. It contains weapon and war machine designs and schemas that must be destroyed. Basher had it once, but I don't have time now to tell you the whole history, and frankly, it'd be better for you not to know."
"Don't listen to him" says Ceshil. "He's a traitor to his own house. I tell you something - I'll give each of you fifty gold pieces. All you have to do is to leave this place and forget you've seen any of us"
Meanwhile Niccolo evaluates their possibilities. They are not so good - the only way out is the door. The walls are solid, and in any case they separate you from a long, long fall as the whole post office floats thanks to the special characteristics of Sharn. Behind the counter where the gnome waits doing his best to ignore you there's a door, but you can see it leads to a small spiral staircase that goes up and you don't remember any other exit from this small building (surely they keep their arcane machines and other magical and mundane means to send signals and messages there)
About the men outside, you'd say they are more numerous than you, but it's difficult to say how many of them there are, since they can easily hide within the crowd, but you can tell they are keeping attention and are ready to intervene at any moment. You also can't see any guard, but you remember there was a small market maybe 150 feet to the west (you can't see the market from here) and maybe you could find a guard or two there. I remind you that he whole place is a net of floating footbridges and platforms.