Desperate to find a cure for his dying wife, Ashley, David becomes obsessed with the legendary Grand Grimoire - an ancient text rumored to contain forbidden rituals for summoning demonic entities to do one's bidding.

Against Ashley and son Henry's protests, David performs the ritual to conjure Lucifuge Rofocale, a powerful infernal spirit, and the Prime Minister of Hell, who is said to preside over all the world's treasures.

Though initially appearing in David's hour of need to promise renewed life in exchange for loyalty, Lucifuge's offer comes at a costly price no family should pay.

It soon becomes clear that the pact has allowed the cunning Lucifuge entrance into their world through David, where the demon can begin exerting an insidious influence on all of them. As Lucifuge's possession of David grows stronger, his personality radically changes, forcing Ashley and Henry into increasingly desperate measures to counter the demon's sadistic whims before he destroys everything they hold dear.

Will Ashley manage to solve the house's mysterious connection to accursed supernatural forces in time to spare her loved ones? Or will her amateur rituals provoke Lucifuge to full chaotic manifestation on an unsuspecting mortal plane far beyond her control?

Only through great sacrifice and sheer force of will, can Ashley and Henry hope to regain their beloved David and head-off this powerful demon in a risky winner-takes-all battle royale. Failure to outmaneuver Lucifuge means their family and souls will be utterly consumed by an active living Evil that will stop at nothing to cross over forever.