Stardock Under Siege

Publisher's blurb: An illithid invasion threatens Stardock, and only you and your allies can stop it! A Four-Hour D&D Epic Adventure for 1st-16th Level Characters. ... Orbiting high above Toril is Stardock, a hollowed-out asteroid used by the Githyanki as a fortress/creche and connected to the Crystal Labyrinth in Undermountain via a magical gate. Stardock was ruled by a cruel githyanki knight called Al’chaia for many years before she was killed by a party of adventurers. Her successor is Urlon, a noble psionic warrior who is a member of the secret society known as Sha'sal Khou.