Entrenched in Madness
The Great War, formerly defined by endless trench warfare, took a dramatic turn after the Battle of Cambrai in 1917. Vast numbers of British tanks managed to completely overwhelm the German defenses, crushing any resistance and securing significant territory in the span of just a few days. The Entente had found their wonder weapon, and rapidly developed new tanks, armored vehicles, and even powered armor.
The Germans were forced to find an answer to this emerging threat. Due to their lack of resources and heavy industry, they could not match the British tank program. Instead, they focused heavily on infantry and chemical weapons, looking for ways to neutralize the Entente's advantage. If they were to survive the war they would need to find their own wonder weapon.
They found this in the Fog. The ultimate chemical weapon, designed to drive enemy soldiers into paranoia and rage upon exposure, and tailored to look like the natural weather phenomena. If the Germans could not destroy the British tanks, they would drive them against themselves in panicked fury. Quickly producing vast quantities of this substance, they planned on utilizing it to restart their stalled Spring Offensive.
It was to be used at the British supply hub of Bergenoît, a quick and easy victory on the road to Paris. Instead, for reasons not understood to any save the gas's creator, the Fog continued to expand long after the British were wiped out. As of two weeks later, over 75,000 men and 150 square kilometers were lost in a constantly expanding region known as the Quarantine Zone. Scouting parties sent into here do not return, either killed or driven to Affliction by the Fog. Those left with their sanity desperately hide in whatever sanctuaries they can find, praying their gas masks aren't faulty.
The nations of the world are reacting to this new development. The Entente are rapidly expanding on their armor programs, planning grands offensives through the Austrian Alps, and even trying to bring the Whites of the Russian Revolution to their side. Meanwhile, the Germans continue to produce the Fog, unhappy about the initial setbacks but satisfied with the potential to block off entire fronts. A new age of warfare has arrived, one that may see the end of Europe.