The Paper Cage is a name for the jail where Japanese Prisoners-of-War were incarcerated by the Stygian government during the Great War; it is also the beginning of the end for the Smiling Lord's plan to control Stygia during the Fourth Great Maelstrom. Several soldiers of Japan died at Port Arthur and were quickly reaped and hidden by the Bleak Legionnaires. Yu Huang had this information leaked to him by unknown parties, and noticed the only returning wraiths were Drones; he sent out attack forces on behalf of the Yellow Springs. However, the Bleak Legion not only fended off the attack, but managed to ship many of the prisoners to Stygia. The Dark Kingdom of Jade attempted negotiations for the return of the Jade souls, but when they refused to give up the Russian souls they had captured, the deals ended, stranding 60,000 Japanese soldiers in the Dark Kingdom of Iron.
The Japanese were forced to build their own prison on the Iron Hills. It became known among the prisoners and their supporters as the Paper Cage. Hirobumi Ito, a former Jade subject and Renegade decided to take advantage of the actions of the Agora Dozen; he arranges for the Grim Legion to take down a group of Loyalists. Confident that they are regaining control of Stygia, they are buffeted by a wave of fierce activity from the Maelstrom. Ito and his Renegades take advantage of the distraction to attack the Paper Cage. It goes down without much of a struggle, showing the cracks in the Grim Legion's facade of control. The prisoners scatter and join with Ito's rebels or attempt to find their own way back to the Yellow Springs.
- , 31-33, 168-169