Hades' men try to take Hercules prisoner, but he beats them up. Then Hades appears and begins firing lightning at Hercules, who passes out and the men take him with them.
When Hercules regains consciousness, he finds himself in the Underworld. Hades tells Hercules he needs his help. He tells Hercules he needs to bring back Sisyphus, who has tricked the spirit of a man named Timeron to take his place. Hades says he can only give Hercules three days because after that Timeron's soul would be doomed to wonder for eternity. Hades tells Hercules he can take Timeron's spirit with him. Hercules and Timeron then find Iolaus, and Hercules explains what they need to do.
Elsewhere, King Sisyphus wants Daphne, Timeron's widow, to come back to live at the castle, but she does not want to. As the three men travel to Corinth, Iolaus tells Hercules that he can see Timeron. Timeron says Hades warned him this might happen if he got too emotional. Iolaus says he cannot go with them to Corinth because there are people who will know him. Hercules says that Timeron will have to wait somewhere until they can find Sisyphus.
When Hercules and Iolaus arrive the guards try to detain them, but they fight the guards and Sisyphus comes and stops them. He tells Hercules he will go with them of his own free will, if Hercules will talk to Hades. When they get to the place where they left Timeron, Hercules tells Sisyphus he should apologize to Timeron for switching with him. Timeron, who is now invisible again, tells Hercules the man they have is not Sisyphus.
The man confesses that Sisyphus said he would care for his family, if the old man took his place back in the Underworld. Hercules says they need to let Sisyphus think his plan worked and they need to hide the old man until they find the real Sisyphus. Hercules tells Iolaus they need to take Timeron with them to make sure they capture the right person.
Hercules leaves Timeron with Iolaus and goes to get some fish. Back at the castle, Sisyphus makes a proposal to Daphne to be his queen so that he can have an heir to his kingdom. She politely refuses telling him that Timeron was the only man she ever loved. When Hercules gets back he tells Iolaus that Timeron is missing and that he knows where he must have gone.
In her chambers, Daphne begins looking through Timeron's things and begins crying. Timeron appears to her and tells her not to, she sees his spirit and runs from him screaming. Timeron, now visible, chases after her and Hercules and Iolaus stop him and pull him out of sight of the townsfolk. Hercules and Iolaus try to sneak into the castle, but are surrounded by Sisyphus' guards. As the archers are about to shoot, Timeron appears and they all run away. The three men go to the castle to find Daphne. Meanwhile, Sisyphus asks Daphne if she has considered his offer to become his queen. One of the guards come and tells Sisyphus that Hercules has arrived with Timeron's ghost. Sisyphus orders them to do anything it takes to stop Hercules and whoever is with him.
In her chambers, Daphne finds Hercules waiting for her. He tells her he is Timeron's friend and he wants to help. He asks her if there is a secret entrance into the castle, so they can capture Sisyphus and get justice for Timeron's spirit. Using a disguise Hercules, Iolaus and Daphne trick their way into the castle, and Hercules makes his way to Sisyphus' chambers.
Hercules says he has to take Sisyphus back, but he tells Hercules that he was called early because of a disagreement with Zeus. He says he is not ready to go, and tries to escape but is captured by Iolaus. Meanwhile, Timeron appears to Daphne, who tells him that she cannot go on without him. She says, "If you canât come back to me-- then Iâll join you." She then runs off crying.
Timeron runs off to find Hercules. He tells him that Daphne has gone to the tower to kill herself. Hercules runs to the tower and pleads with Daphne not to jump. Timeron says they will be together, but he wants her to have a happy life and the wait would be worthwhile. The two manage to convince her and she steps down from the ledge of the tower. They get back to Iolaus and Sisyphus and find Iolaus tied up. Sisyphus orders his guards to take everyone to the dungeon and execute them. Timeron unties the ropes around Iolaus' hands and he and Hercules fight the guards. As they fight, Sisyphus slips away and Hercules chases after him.
As Sisyphus escapes through a secret passage, the queen and Daphne are waiting and knock him out by hitting him in the head. Hercules takes Sisyphus back to Hades and he tells Charon to take him to Tartarus. Hercules asks Hades a favor so that Daphne and Timeron can spend on night together. Hades agrees, but tells Hercules that he will have to borrow a body. Hercules realizes Hades mean his body. Hercules arrives at Daphne's chambers and as he is about to enter, Timeron's body splits from Hercules', leaving Timeron corporeal and Hercules in spirit form.