Pitt locates the quarry and discovers that the robber gang had failed to ascertain whether the ventilation tunnels were actually passable; in fact they were flooded, trapping both robbers and train passengers in the quarry to starve to death. Pitt passes through the tunnels by means of diving equipment and finds the train. Shaw, meanwhile, has mined into the quarry from above and arrives at almost the same moment. There is a fight for the possession of the treaty - which is intact - and Pitt is victorious.