Hercules is aboard a ship taking the mercenary, Derk to stand trial for murder. During a fierce storm, the ship capsizes. Hercules wakes up on shore and finds that he is injured. The mercenary has also survived the disaster, he approaches Hercules and thanks him for saving his life and knocks him unconscious.
When Hercules regains consciousness, he tends to the wound he received when the ship sank. He tracks Derk's footprints on the beach and heads off to follow him. While walking through the forest, Hercules meets Derk, who says they are now even. Hercules does not think this is true, however. He tells Hercules that if he keeps coming after him he will kill him. The two men then begin fighting and Derk climbs a tree to escape and Hercules is almost speared when he springs a trap. Derk warns him again, "Don't follow me."
Derk goes to the river to get some water, he notices a dead bird and taste the water, realizing it is poisoned he spits it out. Hercules tracks Derk to the river and goes to take a drink, but notices the sick animal on the riverbank. Meanwhile, some pirates have found the tracks on the shoreline and deduce that the gold they are looking for was located on the prison ship. Their leader thinks either the gold is on the bottom of the ocean or it has been buried.
Hercules continues tracking Derk, and Derk attacks Hercules, who with only one arm working still manages to fend off Derk until he backs Hercules into a trap and Hercules falls down the hole Derk had dug. In the hole, Hercules finds a huge egg and using some vines pulls himself free as Derk is sleeping. When Hercules gets out, Derk wakes to find him watching over him and Hercules punches him knocking him unconscious. When he wakes, he is in the hole and Hercules is holding him captive there.
Elsewhere, the pirates discover that one of their men has been killed. They think they must be getting near the gold. Hercules gets Derk to dig for clean water and as he strikes through, he tastes it but that is tainted too. Derk says there is no safe water and Hercules says they need to head west. Hercules and Derk find a dead body hanging from a tree, Derk says he has not seen anything that does do such damage. Hercules says, "Sometimes it's what you can't see that can hurt you the most." He reminds Derk of the eggs they had seen earlier.
Meanwhile, the pirates find the camp where Hercules and Derk stayed and find that there is no gold buried there as they had thought. As they continue west, Derk breaks free of his restraints and jumps Hercules; the two men roll down a hill and begin fighting. As they are fighting, a huge sand monster bursts through the ground and grabs Derk's legs and begins dragging him underground.
Hercules attacks the monster and saves Derk's life again. The monster then attacks Hercules and Derk saves Hercules' life. They manage to gain higher ground and their safety, by climbing atop some ruins. Derk thinks they will be there until they rot. Derk makes a deal with Hercules, that if he can see his family once more, he will no longer try to run away. Hercules agrees but only if Derk will help Hercules fix up his wound.
Derk agrees and tends to Hercules' wound. He tells Hercules that he only killed somebody who killed someone else. Hercules says, "Revenge never evens out, it just perpetuates itself." Hercules says Derk should start thinking about the families of the men he kills. The pirates continue tracking Hercules and Derk. Hercules realizes the sand monster has found someone else to feed on and her and Derk go to their aid. Hercules saves one of the pirates and Derk tries to save another. Another tries to escape, but the sand monster follows and catches him. One of the pirates escapes from Hercules and runs away but one of the sand monsters gets him too. Hercules and Derk run to some ruins, where they find some safety from the monsters.
Hercules comes up with some plans to get rid of the sand monsters by turning them against each other. With the monsters dead, Hercules says that the pirates ship, and their water, is east. Hercules takes the ship from the pirates and takes Derk to see his family. Later, Hercules and Derk arrive at his home. Hercules introduces himself and Derk and his wife share an embrace. He explains to her about what he has done and that he has to pay the price for it. His wife says it is unfair, but Derk knows he must face trial for his crimes.
Hercules takes Derk to Sparta, where is tried for his crimes. The magistrate sentences Derk to be executed. Hercules asks if he is going to get a trial, the magistrate says he was already tried and found guilty, Hercules asks if he can have a fair trial. Hercules tries to argue his case with the magistrate, but he says that it is Spartan law. Derk says that the Spartans have their own kind of law, Hercules says it is not right, but Derk, replies, "Neither's what I did."
As the guards prepare Derk to be hanged, an arrow hit the rope and Derk's neck is saved from the rope. Another prisoner takes the opportunity to escape and Derk fights the guards and escapes. He runs into Hercules and asks him if he has come to take him back. Hercules says it was his arrow that split the rope. He thanks Hercules for saving him and Hercules tells Derk he should go back to his family and be a fisherman and put his mercenary days behind him. Derk agrees and tells Hercules that he is always welcome in his home.