From the front cover:
The dungeons beneath Punjar have a history as old as the city itself. The first tunnels were dug by smugglers, which were enlarged by successive bands of rogues, an evolution that culminated in the formation of the first Thieves Guild of Punjar. When it came time to fill the growing dungeon with traps, the Guild hired the legendary dwarf Prester “Trapmaster” Ungart. To ensure that the dungeon's secrets were never revealed, the guild sent a team of eleven assassins to Prester’s residence. In the morning, all eleven assassins were found dead. The Trapmaster the tome containing the dungeon's secrets had vanished. Now, years later, the thief lord Cazül the Chaotic has seized control of the Guild, and his eyes are on the prizes in the tunnels…