From the PDF:
Welcome to the Dungeons & Dragons: The Movie adventure. This is an introductory product designed to be
used with the Dungeons & Dragons Adventure Game.
You defeated the Great Maze in the Antius thieves’ guild, only to discover that Xilus used you to get the Eye of the Dragon for him. Before you could fight the entire guild to keep the gem, Damodar and his Crimson Guard broke in. Outraged at the intrusion, Xilus ordered his thieves to defend their hall. In the resulting confusion, you tried to escape, but there were more Crimson Guard at all the exits.