Slave Pits of the Undercity (Advanced Dungeons & Dragons module A1)

It is time to put a stop to the marauders! For years the coastal towns have been burned and looted by the forces of evil. You and your fellow adventurers have been recruited to root out and destroy the source of these raids. But beware, hundreds of good men and women have been taken by the slavers and have never been seen or heard from again!