Résumé: While testing out a new experimental jet for Tony Stark, The Thing accidentally crashes the ship, unearthing an ancient cavern. When Stark goes after him as Iron Man and finds Thing had revived Prester John, Prester then uses the Stone of Power to take control of both Iron Man and the Thing as part of his plot to take over the world.
With the two under his thrall, he tells them that after his encounter with the Human Torch and Wyatt Wingfoot, he wandered the desert where he was found by the Bedouins who worshiped him as a "being from the heavens" and they gave him the Stone of Power. This caused Prester to believe he was a god that created the universe. The stone would eventually suck him into the Earth and put him in a state of suspended animation.
Iron Man and Thing manage to shake loose of Prester John's control and attack him. During the fight, the two heroes manage to destroy the Stone of Power, freeing Prester from its influences. With Prester John free, he thanks the two heroes for his help and agrees to join them for a meal.