The protagonist of the game is Al Simmons, an undead being. Simmons used to work as a secret agent for the U.S. government, but was betrayed and murdered by one of his own.[4] Longing after his wife, a deal was made with the Lord of Darkness named Malebolgia to make Simmons return from the dead and thus become Malebolgia's Spawn.[8][4] In the deal, Simmons would get access to infinite powers. Unfortunately, the powers, though infinite in force, were limited in supply. If Spawn's powers are used to their full extent, his soul will belong to Malebolgia and he will do Malebolgia's bidding for all time to come.[8]

In present time, a renegade crusader named The Mad One has kidnapped thirteen innocent children, including Simmon's stepdaughter, and locked their souls in a magical orb called Orb of Purity. The Mad One's long-term goal is to make use of the Orb of Purity to destroy Malebolgia once and for all, and he has already entered the area where Malebolgia resides.