Ya'shenn looks back toward the warlock, and belatedly explains: "A ghaik will be nearby, I am almost certain. Others seek it, but I can hardly let them fight alone."
She doesn't add that in her weakened state, she'd hardly be of much use, anyway. Especially against a Tamer, if Mim's watcher happens to belong to that creed. While she may be... a bit lapsed, Ya'shenn is still a Githyanki, and can't suffer the thought of an illithid getting away alive. Especially since it undoubtedly aims to cause even more trouble for them later.
Du'minh and Vivec search around the builing for likely hiding places for an illithid. Void Keys sits at the very top of Silver Void Street, directly opposite the huge, sprawling, Silver Void Steelworks. That is out, for it is a busy place, churning out smoke even at this post-antipeak hour. Silver Void Street terminates on Swans Way, a street far more like metropolitan Sigil than the ghetto of Git'riban. Swans Way is a wide street, perhaps twenty feet or more. Several businesses and apartments are within 100 paces of Void Keys, though it might be expected that these have been screened by the Silver Eyes. Far more likely, there is a place just under one hundred feet into Undersigil where the ghaik hide.
There are a few manhole covers up the street. Swans Way, considered "Sigil", not "Git'riban" has a sewer system in better repair than is typical in the githyanki ghetto down the hill.
One hundred paces back down Silver Void Street brings one into The Tunnels, crowded tenements built into every concievable space, above street level and below. An illithid would have a difficult time hiding here. Unless ... Unless it had a portal to the interior of one of the 'closed doors'.
You see, few blokes really pay rent in Git'riban. Instead, somebody looking for a kip will either pay a 'landlord' to find one for them, or try to stake out a place of their own. Empty apartments are usually heavily trapped (by the local 'landlords' who everybody hates because a lot of 'em are Sharpshadows), so unless one is a professional, it pays not to open a door that's closed. The custom in Git'riban is to leave a door open if expecting business or visitors. Merchants rarely put up signs (unless on the fringes of the ghetto or otherwise catering to barbarians as well as gith), and residents just know where to go and who to talk to if they need someting.