MacGyver goes to a remote tavern in the Taurus Mountains of Turkey to meet with Beth Webb. She's busy playing dice against Kunush, a man who has one of three pieces of an Egyptian plaque. Kunush tries to back out but Beth accuses him of cowardice and dares him to play one last game for the piece. As they play, MacGyver arrives and an old enemy notices his arrival: Hakim, a black market dealer in stolen antiquities.
Beth wins the dice game, but Kunush attacks her. MacGyver comes to her aid and after a brief fight, they manage to grab the Egyptian piece and escape. As they drive away in MacGyver's Snowcat, Beth explains that she's working with Professor Axford, who has the unpopular theory that Alexander the Great was buried in Turkey rather than Egypt.
The pair arrives at the construction site and Professor Axford greets them. Hakim has secretly traveled there and watches from hiding. Beth gives the piece to Axford, who has the second piece. The Phoenix Foundation purchased the third piece and MacGyver turns it over. Axford assembles the three pieces into the complete plaque while explaining that each piece belonged to one of Alexander's trusted generals. The three men sealed Alexander into his tomb and then split the plaque which contained the secret to finding and opening it. Axford also has Alexander's last will and testament, which Axford claims verifies his claim that Alexander was buried in Turkey. The hieroglyphics on the plaque talk of a heavenly battle which resulted in Osiris plucking his own eye out and casting it down to the earth, bringing light to the world. The tomb, the Eye of Osiris, was built on the spot. The hieroglyphics also speak of how anyone entering the tomb must pay tribute to Anubis and the Keys of Life, and that only the pure of heart can pass through the Maze of Eye. Finally, the plaque reveals that those who would enter Alexander's tomb must earn the favor of the sun god Ra.
In the morning, the workers find a statue of Ra and bring it up from the underground chamber. The statue holds a staff that pointed west, the direction that the Land of the Dead lies in Egyptian mythology. The workers lift the statue by crane and Hakim uses a remote to set off an explosive charge, severing the cable and sending the statue crashing to the ground. The workers insist that the Eye of Osiris is cursed and start to panic. Axford and Beth examine the area and find a plaque inscribed with the Eye. Meanwhile, Hakim slips into their tent and steals the plaque and the will. When Axford yells at the workers, a startled Hakim drops the plaque upside down into a box of dirt. MacGyver examines the cable and realizes that someone sabotaged it as a distraction. They run to the tent and discover that someone has stolen the artifacts.
Hakim goes to the truck he has ready for an escape. He tells his accomplice to drive away but realizes that the man is dead, shot through the head with a single shot. The killer, a blonde German, comes up behind Hakim and asks why he's interfering with his plans.
As MacGyver and the others examine the tent, he sees the imprint in the dirt. Axford warns that the dirt won't hold the impression under the weight of plaster, but MacGyver sprays it with sugar water. When the sugar dries, it hardens the pattern and lets them make a plaster mold.
The killer tells Hakim that he's Nicholas Von Leer, an infamous black marketer. He's arranged the sale of the plaque piece to the Phoenix Foundation to lure MacGyver to Turkey. Von Leer plans to acquire the Eye of Osiris and Hakim warns him that he's the only one who can read the plaque. He offers his services and Von Leer agrees to take him on as a partner.
MacGyver completes the plaster mold and Axford tries to decipher it without the stolen will of Alexander. He snaps at them and leaves, and Beth admits that the professor is her father. His wife left with Beth for America when she was young, unable to live with a husband obsessed with the past. After her mother died, Beth begged Axford to take her with him and he reluctantly agreed. After studying the duplicate plaque and a local topographical map, MacGyver goes to follow a hunch. However, he stops long enough to ask Axford why he's treating Beth so harshly. Axford defends his actions, insisting that he isn't treating her any different than anyone else, but MacGyver suggests he should treat his daughter a little differently. The professor snaps at him for interfering and tells MacGyver to mind his own business.
In the wilderness, MacGyver finds a creek with black rocks, tektites. He checks the hieroglyphs, which speak of the earth singing and the mountains dancing.
Back at the camp, Beth finds Von Leer waiting for her to talk privately in her tent. They already have an arrangement: Beth joined the expedition to take photos and Von Leer offered her money for them so she could pay off her dead mother's debt. Axford calls her out to apologize for his behavior and Beth begins to have second thoughts. MacGyver returns and explains that the tektites were created by the Eye of Osiris, which generated enormous heat when it crashed to the earth. Von Leer listens in as MacGyver speculates that the Eye of Osiris was a meteorite the crashed to in the region and the locals mistook it for a divine event. Going over the topographical maps, MacGyver deduces where Alexander's tomb is and they take a Snowcat to search.
In the crater, they find a rock formation which Axford identifies as the Pillars of Osiris. They find an eye marking with a hole for a pupil and MacGyver inserts Ra's staff. A door in the pillars opens and they go inside to find a burial chamber with sarcophagus and a statue of Anubis, his arms extended. Von Leer and Hakim come in behind them and take them prisoner. Von Leer explains that he's the brother of Erich Von Leer, who died during the search for the Holy Rose. Beth insists that they're deal was only for photos but Von Leer tells them that the deal has changed. Her father is shocked to hear that she planned to betray him. Von Leer orders them to open the sarcophagus but nothing is inside. A mechanism seals the door, trapping them.
Von Leer prepares to kill them all but MacGyver says he'll find a way out if he spares Beth and he father. Von Leer agrees and MacGyver remembers the hieroglyph talking about paying tribute to Anubis. Beth finds a jar with Anubis' image inscribed upon it and MacGyver places it in the statue's arms. That opens another door and Von Leer sends MacGyver through a narrow passageway to the magnificent chamber beyond. It's lit by sunlight refracted through a vein of crystal carved in the shape of an eye. At the far end of the room is a gold sarcophagus with a cagelike arrangement on top, divided into four disks. The others come through but when Hakim gets stuck, Von Leer casually shoots him dead and warns that a similar fate awaits the others if MacGyver doesn't open the sarcophagus. As MacGyver examines the sarcophagus, Beth apologizes to her father, who he admits he can understand why she hates him after he ignored his wife so long.
MacGyver realizes that the cylindrical arrangement represents the Tree of Life, which represents the four elements of fire, water, earth, and air. There is a fountain nearby and a jar containing Greek fire. Realizing they represent the key, MacGyver places the Greek fire in the lowest disk. He then puts water in the disk above. The heat turns the water into steam, air, and it condenses on a rock in the center, earth. The condensation drops down onto a platform and the weight opens the sarcophagus. Inside is Alexander's corpse, and in its arms is an enormous blue sapphire: the remains of the meteor, carbonized by its descent through the atmosphere.
Von Leer grabs the sapphire and the corpse seems to reach out for him. It triggers another mechanism, sealing the doors and causing the walls to close in from either side. Remembering the reference to the Maze of the Eye, MacGyver realizes it refers to the quartz eye. He takes the sapphire from Von Leer and puts it in the quartz mounting. The resulting beam shows a small disk below the sarcophagus which covers a switch opening another doorway. Beth and Axford leave while Von Leer runs to grab the sapphire. MacGyver tries to warn him but Von Leer takes the sapphire and the walls start moving. He laughs in triumph... and a huge stone block slams through the quartz, crushing him to death. It slams through the room and through the new doorway. MacGyver, Beth, and Axford run down the passageway with the block sliding behind them. They take refuge in a narrow depression and the block comes to a halt above them, sealing them in. On the underside is another drawing of the Tree of Life. MacGyver presses the four elements in sequence and the floor of the depression falls out, dropping them into a cavern below. They get out just in time before the block drops, sealing off Alexander's tomb forever.
The trio goes back to the camp and Axford tells his daughter that it's time they put the past aside and look toward a future together. MacGyver assures Axford that the important thing is finding the truth about the past, not just artifacts.