CM4 "Earthshaker!" a high-level adventure (levels 18-22) centered around a gigantic, mobile automaton. It is compatible with Expert or Companion D&D, or Basic Fantasy RPG and other retroclones.
The adventure begins with the player characters acting as seneschals, managing a dominion while the Duke is away. They must then contend with the arrival of Earthshaker, part of a traveling exhibition, and thwart a villain's plot to control the automaton using a powerful gem. The module includes detailed maps, character sheets, and rules for Earthshaker's operation and the consequences of its actions, including the potential for widespread destruction. The adventure concludes with the players facing diplomatic consequences and the eventual fate of Earthshaker, whether its destruction or its return to the control of its gnome operators.