| Director | Richard Donner |
|---|---|
| Budget | $80 million |
| Box office | $43.9 million |
Castlegard, a village near La Roque Castle in Dordogne, France, is the site of the 1357 hanging of Lady Claire, sister to Arnaut de Cervole. Her martyrdom led France to win the Hundred Years War against the English. While excavating a nearby monastery, an archaeological team finds a sarcophagus containing the remains of a French knight with a lopped ear, holding the hand of his lady, an unheard-of practice for the time.
Professor Edward Johnston, the team's leader, travels to New Mexico to the headquarters of the ITC Corporation, his project's sponsor, to learn if they have tampered with the site. Johnston's students Kate Erickson, Josh Stern, and François Dontelle, along with Scottish archaeologist André Marek; and Professor Johnston's son Chris, discover a lens from Johnston's bifocals and a note begging for help, although both date over 600 years old. ITC later invites them to its headquarters.
In the process of developing teleportation technology, ITC locked onto a stable wormhole to 1357 Castlegard. Johnston was invited to see the past for himself, but his group has not returned, and ITC wants Marek and company to go back in time to locate him. ITC vice-president Steven Kramer revealed that the device they built was meant to teleport items to certain locations, but came across a wormhole that leads only to 1357 Castlegard. All but Josh volunteer to go.
The volunteers are stripped of all modern technology save for markers they can use to initiate their return. They are joined by a security team including ITC's head of security, Frank Gordon, who recently recovered the body of a teammate named Taub, and two former Marines. On arrival in 1357, the team appears in the path of a young woman chased by English knights; the 2 security men are killed while protecting the group, although one activates his marker after priming a grenade. When his body arrives in the present, the grenade detonates and shatters much of the teleportation device. Josh aids Kramer in making repairs in order for the team to return as they had less than 6 hours.
The team evades the knights, and the woman leads them to the English-controlled Castlegard. They are captured and brought before Lord Oliver de Vannes and his second-in-command, William DeKere. When interrogated and discovered to speak the English tongue, the team members claim to be Scottish. After hearing Dontelle's dialect, De Vannes kills François, believing him to be a French spy. The others are imprisoned in the attic along with Johnston, who previously promised de Vannes that he could make Greek fire for the English in exchange for his life. They escape but are pursued by the English while Marek help the woman break away. Marek is lead to the French forces and the woman reveals herself as Lady Claire and meets her brother, Sir Arnaut de Cervole. Marek soon believed he changed history by saving Claire.
Arnaut provides Marek with a weapon and a horse to find his friends. The English ambush Arnaut and his men but the French prevail, while Marek is recaptured. Chris, Edward, Kate, and Frank are discovered by DeKeres' men and soon realize their markers are not activating. Edward and Frank are recaptured while Chris and Kate once again evade the English. As Edward, Frank, and an unconscious Merek are in his possession, DeKere reveals himself to Gordon and Johnston as former ITC employee William Decker; he had frequently used the teleportation device but was not told by ITC that each use damaged his DNA until it was too late, at which point he would die on a return trip. He plans revenge on ITC and kills Gordon. De Vannes orders his knights to march on LaRoque castle while torching Castlegard, and DeKere brings Johnston and Marek along.
Kate and Chris arrive at the future archaeological site to find it was a monastery, and with the help of the monks, they find a secret passage that leads to La Roque. As the battle commenced, the monks alert de Cervole, who arrives with some soldiers for the surprise attack. Kate and Chris help to swing the upcoming battle in the French's favor by leading de Cervole's men through the monastery tunnels and into the castle.
During the battle, the Greek Fire is tested and Claire is captured and set to hang. Refusing to allow this, Marek blows up the laboratory where the Greek Fire was made, distracting the English, and frees Johnston, while Chris helps de Cervole defeat de Vannes. Enraged, DeKere slashes off Marek's earlobe, and Marek realizes that he is destined to be the knight in the sarcophagus. Marek defeats DeKere, recovers the markers, gives them to the others, and says his goodbyes while running off to help the French assure victory and restore history.
In the present, Josh and Kramer finish the repairs. ITC president Robert Doniger, who tried to sabotage their attempts, fears that when the students' stories become public, ITC will suffer financially. He accidentally injures Kramer. As the machine activates, Doniger races into it, attempting to block the teleportation, but instead is sent back to 1357 with no marker or way of returning, where he arrives outside the castle and is presumably killed by a charging knight.
Chris, Kate, and Johnston safely return while Marek chooses to stay behind. Later, the team returns to the Castlegard ruins, re-examines the sarcophagus, and finds that Marek and Lady Claire lived together after the war and had three children: Christophe, Katherine, and François.