Warcraft: The Beginning

Warcraft: The Beginning is a cinematic retelling of the first Human vs. Orc conflict as depicted in the Warcraft franchise.

Plot
The movie opens with Gul'dan, a prominent orc Warlock opening a portal between the orc homeworld Draenor and the world of Azeroth, using the life-force of captured prisoners to do so. As the orc Horde ravages the new lands they encounter in Azeroth, it becomes clear to Durotan, leader of the Frostwolf orc tribe, that where Gul'dan treads, death swiftly follows.

Meanwhile, the humans of Stormwind discover the presence of Fel magic in their lands, a remnant from an ancient enemy known as the Burning Legion. Khadgar, a member of the Kirin Tor that had renounced his vows to the brotherhood of magi in Azeroth, is told to seek out, Medivh, a Guardian of Azeroth.

The orcs capture human prisoners located in the Black Morass, and construct what would later be known as the Dark Portal.

Later on, it is revealed that Medivh himself was in communication with Gul'dan, and due to the presence of Fel magic within him, Medivh was manipulated into leading the orcs to Azeroth; as his corruption bubbled to the surface, Medivh completed the incantations necessary for the Horde to teleport a sizable military force to Azeroth through the Dark Portal. After Khadgar and Anduin Lothar overcome Medivh, he momentarily regains control of his faculties, and uses arcane incantations to cause the Dark Portal to open a portal to Stormwind, where the remaining prisoners are evacuated to before it closes, leaving King Llane Wrynn and Anduin Lothar trapped.