In an alternate universe shaped by Norse mythology, the Nine Realms and their races were created by a central artifact called the Monolith. Generations of conflict and an old prophecy have left the realms collapsing, with the Prime civilization falling to ruin as an undead army spreads across the universe, signalling the End Times. An unnamed Prisoner, suffering from amnesia after a long imprisonment, is released by Aras, the Prime caretaker of the Monolith, in a last attempt to hold off this fate. Tasked with repairing the Monolith by restoring the Nexus Orbs that power it, the Prisoner travels across worlds ranging from a lifeless snow planet to a human forest world and an abandoned homeworld, fighting through the undead that now overrun them.