From the back cover:
"Put out the Sun; Darken the Light!" -Illithid aphorism
I watched the early morning sun dribble above the horizon, only to have my worst fears realized. As I looked on, something vast and unseen took a monstrous bite out of the sun, leaving gaping teeth marks. The bloated red disc guttered and spit, finally plunging back below the horizon like a wounded bird in flight, dousing the plain in stygian darkness.... And I knew what I had long suspected: They had returned!
Something is very wrong in Stormport: Corruption runs rampant among city officials, more and more people turn up missing every day, dark prophesies of Change convert new believers, and rumors persist of a demonic beast with a taste for human flesh that stalks the alleyways. Worse yet, spring is overdue; winter refuses to relinquish its icy grip.
Only one vile force could cause such chaos: The Illithids have risen up once again, ready to enslave the surface races. Now, as never before, the world needs great heroes, mighty adventurers who will challenge the illithids' dark agendas.
A Darkness Gathering is the first of an adventure trilogy (continuing with Masters of Eternal Night and concluding in Dawn of the Overmind) that pits brave adventurers against the brain-eating mind flayers. Dungeon Masters can run each individual adventure of the trilogy separately, or they can be linked together to form a seamless, epic-length adventure.
The illithid trilogy supports The Illithiad, a MONSTROUS ARCANA supplement that provides invaluable supplementary information on mind flayers and their evil plans."