In 1944, archaeologist Indiana Jones, along with his Oxford colleague Basil Shaw, infiltrates a Nazi-occupied castle in the French Alps to reclaim the Spear of Destiny. However, their mission takes a turn when they are captured by the Nazis. During this time, Nazi astrophysicist Jürgen Voller examines the Spear and determines it to be a forgery. Nevertheless, Voller reveals that he possesses something far more significant—a fragment of the "Archimedes Dial," an extraordinary artifact crafted by the ancient Greek mathematician Archimedes using Antikythera mechanism technology. The Dial is said to detect temporal fissures, granting its wielder the ability to travel through time.

Amid the chaos, Jones manages to escape and boards a train loaded with looted artifacts. A fierce confrontation with the Nazis ensues, during which Jones rescues Basil and wrests the Dial from Voller’s grasp. The duo leaps from the train just before Allied forces intercept it, narrowly making their escape.