Mathayus aims to avenge the death of his father at the hand of Sargon, now king of Akkad, by taking service in his Black Scorpions squad. After completing his training he is tasked by Sargon to kill Noah, Mathayus’s own brother. He saves him and escapes the city, but a magic arrow follows them and kills Noah.

Mathayus boards a ship to Egypt, accompanied by his childhood friend Layla. He intends to get the Spear of Osiris in Egypt, which he believes will be able to pass through Sargon’s black magic protection. A fellow traveller, Greek poet Aristophanes (Ari), tells Mathayus and Layla that the Spear only kills Egyptian creatures, but the Sword of Damocles will work. The trio travels to Greece, where they can enter the Underworld to retrieve the Sword of Damocles. On the way, they fall into a cell and are surrounded by men left as sacrifices for the Minotaur. Some of the sacrifices are mercenaries who owe allegiance to Mathayus’ father, so they help him and Layla to defeat the Minotaur, with help from a Chinese captive named Fung.

The enlarged group travel to the Underworld, where they are attacked by the goddess Astarte. Layla and Astarte fight, while Fung and Ari search for and find the sword. Astarte tries to send Layla to hell, but Mathayus frees her, and they all escape to the human realm.

Astarte orders Sargon to get her sword back, and he asks for more dark powers. The group reach Akkad, where Sargon turns on a machine that dumps oil into the water supply. The oil and water begin to flow through statues into the city, which is then set on fire.

Using the Sword of Damocles, Mathayus fights through to Sargon but finds his own father, who turns out to be Sargon in disguise. Sargon uses the confusion to disarm Mathayus and they begin fighting. Ari picks up the sword then hands it to Sargon, revealing that he had been bribing Ari with riches. More chaos and fighting ensues in the city and we learn that the sword that Ari gave Sargon was a fake and easily shattered. Ari bursts in and gives Mathayus the real sword. When Sargon states Mathayus owes him his loyalty as a black scorpion, Mathayus burns off his scorpion tattoo with the sword as Sargon retreats into the shadows.

Sargon turns into a giant near-invisible scorpion and continues his attack. Mathayus impales the Scorpion King Sargon with the Sword of Damocles. Layla manages to put out the fires while Fung fights and eliminates several of Sargon’s soldiers. Astarte tells Mathayus that she will show him no mercy, but Mathayus tells her that she will have him one day. Mathayus awakens in a bed after being nursed by Layla, who then tells him that he has won the right to be king, but he decides for now to head off on a life of adventure, knowing one day he shall be the Scorpion King.