After 75 years of peace the races of Shea go back to war. The Dark Elves unveil the dragon ships, built from dragon bone and armed with bolts of necrotic energy.
Once Shea has been reduced to ruin the Humans turn to a forbidden and ancient magic to repair or reanimate their maimed or dieing forces. A new race is born, the Warforged, immortal soldiers with the mind of a man and the body of a machine.
Whether a result of the carnage, or the magics that have been wielded throughout the war the boundaries between the land of the dead (the Shadow Lands) and physical reality have been shredded around around Shea.
Once political avenues proved non-successful the dwarves took up the war banner against the humans, intent on reestablishing the natural order of life and death, and preventing any further damage to the planes of reality.
For the first time in history this has placed the Dwarves and the Dark Elves on the same side. Luckily for the Humans the distrust between these two has prevented them from presenting a coordinated offense.
The Elves have proven themselves eager allies of the humans and while they maintain an independent command structure intelligence is shared freely between the factions and joint military strikes on targets of interest are common.