The inventor, Daedalus wakes from a nightmare in which his son, Icarus died after flying to close to the sun while testing out his father's invention: a pair of giant wings. Daedalus is angry with himself for letting such a thing happen. Meanwhile, Hercules is helping the people of a nearby town as they prepare for the coming floods. While helping, he meets Katrina, a scribe. She tells Hercules she is traveling to Euboea to meet Daedalus, and she heard that Hercules knows him. Hercules confirms this and she asks if he can tell her something interesting about the inventor. He says he is a great father and his son's name is Icarus. Katrina corrects him, telling Hercules that Icarus is dead and Daedalus is responsible.
Hercules says that he will accompany Katrina on her trip to Euboea. On the way she asks him questions about Zeus being his father and his relationship with Hera. Along the road, they meet some people fleeing from soldiers and Hercules goes to stop them, with Katrina tagging along behind recording all the action. Hercules finds out that the soldiers weapons were made by Daedalus.
Elsewhere, King Nikolos toasts to Daedalus for his great weapons. Daedalus is working on his latest invention: the Megalith. Katrina and Hercules arrive at the village and ask to see Daedalus, but the guards will not allow them to enter unless they have permission from the king. Hercules leads Katrina away and he uses some rope to get over the castle wall. Elsewhere in the castle, Daedalus has almost finished the first Megalith. The Megalith ready to be demonstrated to the king.
Hercules finds Daedalus and gives him his sympathy over Icarus' death. When Katrina questions Daedalus about the crossbow he confirms that he did design it, but that it belongs to the king; his job is to invent, not pass judgment. Daedalus excuses himself saying that he has work to do. Perdix, one of Nikolos' guards, informs him that Hercules is present in Euboea. Nikolos asks if the Megalith is ready, because the next time he fights Hercules, he will be the one who wins.
Katrina thinks Daedalus has lost his conscience, but Hercules says she does not know him well enough to pass judgment. He says that Nikolos is taking advantage of Daedalus' grief and that he will go and speak with Daedalus alone. Perdix comes and tells Hercules that Nikolos requests his presence at the castle. Hercules goes with Perdix and the soldiers.
Nikolos informs Hercules that Daedalus came to him begging for funds to help him build his inventions. Hercules says that when he has put his grief behind him, Daedalus will realize what Nikolos is doing.
Katrina goes to talk to Daedalus and asks him for his side of the story regarding his son's death. He calls the guards and they get rid of Katrina. Later, Hercules comes to talk to Daedalus. Daedalus defends his actions saying that Nikolos has the right to defend his people from renegades. Hercules says Nikolos' soldiers were using his crossbow on defenseless farmers. He tells Daedalus that he is allowing his grief to obscure his judgment.
Elsewhere, Katrina is taken to the king, who persuades her to stay so that she can report on the demonstration of Nikolos' new military weapon. While Hercules looks around the marketplace, Perdix, inside the Megalith begins rampaging. Katrina pleads with Nikolos to call of the Megalith but he says she should be taking notes to report what is happening.
Hercules grabs a boiling pot of a nearby fire and throws it into Perdix's face, he falls to the ground screaming. As Perdix vacates the Megalith, Hercules smashes it to pieces. Nikolos begins arguing with Daedalus, saying that he told him the Megalith was invincible, but Hercules just destroyed it. Daedalus is angry with Nikolos for lying to him, saying that Hercules will think he has betrayed him. Daedalus attempts to leave, but Nikolos says he will finish what he has paid him for or Daedalus will not get out of Euboea alive.
In his lab, Daedalus promises "Icarus" that he will make things right. Daedalus tries to destroy the second Megalith, but one of the soldiers knocks him unconscious and leaves him inside the burning building. Hercules comes to rescue Daedalus and fight the guards. Later, Daedalus explains what happened after Icarus died. Hercules says he cannot change the past and that he needs to tell Nikolos that he will no longer work for him.
Meanwhile, the guards have salvaged some of the parts of the Megalith and Nikolos says he will be the one inside this time because he wants the honor of killing Hercules himself. Daedalus tells Hercules that there is a second Megalith. Hercules says he will go face it alone. While waiting for his return, Katrina apologizes to Daedalus for not being sensitive enough when she was asking him questions earlier and gives her sympathy for Icarus' death. He wishes he had died instead of Icarus but Katrina says he still has the ability to do good in the world.
Tired of waiting for Hercules to return, Daedalus and Katrina decide to ignore Hercules and go to help him. Hercules arrives back in Euboea and begins fighting Nikolos inside the Megalith. He grabs another boiling pot, but it is empty. Hercules eventually defeats Nikolos with another of Daedalus' inventions. Hercules tells Daedalus to go back to inventing things that will help mankind, Katrina says she would like to write that story. She tells Hercules that he is a hero in the true sense of the word and Hercules suggests that she write a book. She says that is a good idea, but she would have to change names and the story would be fictionalized or no one would believe it.