King Thrym is the ruler of the Frost Giants of Jotunheim, a monarch bound to Asgard by a fragile and long-strained truce. When Thor trespasses into his realm and slays two of his sentries in the theft of the Sword of Surtur, Thrym declares the peace accord broken and marshals his armies to march on Asgard, demanding the fire sword be surrendered by sunrise or the war will proceed.
For all his readiness to make war, he proves a ruler of measured judgment. He holds his forces at the agreed hour rather than striking early, honoring the terms he set with Odin. When Thor humbly returns the sword and offers himself as prisoner, Thrym weighs the two sentries lost against the countless lives spared by the weapon's return. He accepts the peace, spares the young prince, and sends him home to tend to his wounded father, ending the conflict rather than pressing his advantage.