Showdown is the events of Might and Magic V: Darkside of Xeen. With Lord Xeen destroyed, King Burlock enlisted the Defenders of Xeen to journey to the Darkside of Xeen and combat the rogue Guardian Sheltem (calling himself Alamar) once and for all. Meanwhile, the dragon pharaoh attempted to contact his allies, only to discover all had been imprisoned or reneged to Sheltem's side.
Arturius, Rebecca, Tyro, Badger, Zippo and Seymour progressed to the Darkside, following in Prince Roland Burlock's footsteps. Emerging in the town of Castleview, they were approached by the herbalist Zelda, who presented the strangers an orb she had located at the base of a cliff. Unbeknownst to her, the orb belonged to the Dragon Pharaoh, sent out in a last gambit. Playing their journey by ear, the six adventurers sought out and rescued the wizard Ellinger, who instructed them to restore the quasi-physical Castle Kalindra to reality using energy discs.
In Sandcaster, the adventurers encountered Sheltem's minions, the master wizards and enchantresses led by Xenoc and Morgana. Killing the spellcasters and liberating the city, they continued traversing the dungeons of the Darkside, mustering enough discs for Ellinger to restore the Castle. Inside, they learned that Queen Kalindra had been captured by the Vampire Count Blackfang, another of Sheltem's allies.
With the aid of the Kalindran Knight, Ambrose, and his Griffin, the adventurers infiltrated Castle Blackfang. After destroying the Count, they discovered Kalindra herself, only to learn that she had been turned as well. With her lost crown's powers, they were able to restore her to humanity, and journeyed to the Tomb of the Dragon Pharaoh with her aid. There, they returned the Pharaoh's orb to him, and learned more of the nature of Sheltem. The Pharaoh explained that, using Xeen's Cube of Power, Sheltem was directing the nacelle of Xeen through the Void towards his planet, Terra, attempting to use it as a vessel to build a world-empire against the Ancients who created him.
To combat Sheltem, the Pharaoh informed the adventurers of the second escape pod from Terra - that of Corak the Mysterious. It had landed in the northeastern lava fields, effectively imprisoning Corak and preventing him from destroying his nemesis. After breaking into the pod and rescuing Corak, the adventurers formed an alliance with the Guardian. Corak's plan was a simple one - with a Soul Box, he could be taken to Castle Alamar in secret to confront Sheltem and end his rampage.
The adventurers travelled to Olympus with the help of Lucio, the Gods' ferryman. There, they obtained the Soul Box they required, and returned to the physical realm. With Corak hidden, they launched their attack against Sheltem's hordes, confident that Sheltem himself considered them unworthy of his time. After fighting their way to the throne room, they cast the box inside, and Corak emerged, shocking his opponent. Sheltem then removed his mask to reveal his disfigured countenance, and the two fought in a battle of techno-magic. The epic skirmish ended in a stalemate, but to ensure the safety of the Ancients' empire, Corak sacrificed himself using Code 0-0-1, destroying Sheltem along with him.
In the aftermath, the adventurers and the Dragon Pharaoh lamented Corak's demise, gathered their allies and prepared for the Unification Ceremony.