Jallarzi's countenance turns suddenly stern at the mention of the Silver Key of Portals. "I see you wish to cut to the quick. Very well."
She moves over to a shelf upon which rests a small, nondescript wooden tinder box. Of all the magnificent items on display throughout the room, you reckon it must be the most mundane of them all. You would have never noticed it had she not drawn your attention to it. She retrieves the box from the shelf and takes it in her hands before her. Then, leaning ever so closely so that her lips almost touch the lid, she appears to whisper words so soft you would be surprised if she even uttered a sound at all. As she finishes, the latch to the box snaps suddenly open. Jallarzi slowly opens it so that the back of the lid faces her. You can see inside the tinder box is a very plain tarnished silver key.
"This is the very key that Mordenkainen and his then apprentice, Bigby, used to gain egress into the levels below Maure Castle many years ago. I will loan it to you on one condition only. During Mordenkainen's expedition, his group came across a demon-handed man who was obsessed with the castle and it's lore. Mordenkainen and Bigby slew him, and left the dungeon for other adventures, but recently, there have been signs. The fact that you are being asked to investigate this dungeon is one of them. There are those who fear evil may have waxed in the time since the last expedition to this place. If you find that this is true, you must promise to lay to rest any such evil, as the portents I have seen if nothing is done bodes ill for the entire region."
Jallarzi holds out the tinder box containing the key, implying that by accepting it, you agree to her terms.