Keltus, an agent of the ruling Order, is on the trail of the enigmatic Shadow cult. He reports to a local garrison to interrogate a captured Shadow cultist, but finds the man dead - murdered by Nemyt, an elven bounty huntress cursed with the Mark of the Shadow - an undead plague. Nemyt has learned of a secret meeting and a powerful treasure. Keltus frees her from prison and the two set out to rendezvous with the cult.
En route, the pair team up with Kullimon the Black, an infamous orc raider. The three heroes must battle undead creatures, river dragons, swamp monsters, gun-totting dwarves and a horde of orcs in order to reach the meeting point, where their plan for Nemyt to pose as a Shadow Agent goes horribly wrong. Nemyt is captured and the real Shadow Agent escapes with the treasure, which he will use at the Well of Demons to raise an Undead God..
Keltus and Kullimon battle their way to the Well, freeing Nemyt in the process. The Shadow Cult has completed a hellish ritual and a massive demon rises from the Abyss. The heroes defeat the fiery demon in an epic duel, banishing it to the Underworld, and save the realm from the undead menace.