Hans arrived in Arendelle for the coronation of Queen Elsa, though unbeknownst to anyone, he secretly intended to marry Elsa's younger sister Anna, murder Elsa and claim Arendelle as his own. However, he masked his true intentions with that of a benevolent royal, and Anna soon became infatuated with him. During the coronation party after Elsa was crowned queen, Hans and Anna shared a duet which transformed into an entire date, ending with Hans proposing to Anna, who readily accepted.
However, Hans was caught off guard when Elsa revealed her powers over ice and snow and fled the kingdom soon after, unintentionally setting off an eternal winter over the kingdom. Anna, feeling guilty for the events leading up to the curse, volunteered to return Elsa to Arendelle and left Hans in charge in her absence. With both princesses gone, Hans started to gain the freezing townspeople's trust so they would more easily accept him as king.
After Anna's horse returned without her, Hans came to the conclusion that Anna was in danger, and, along with several royal guards, went off to Elsa's ice palace to free Anna and detain Elsa. Unbeknownst to Hans, The Duke of Weselton secretly ordered his bodyguards to murder Elsa on sight. Upon reaching Elsa's palace, Hans was attacked by Marshmallow, a snow golem created by Elsa to guard her. However, he managed to subdue Marshmallow and cause him to plummet off the cliff to his apparent death. Hans then prevented one of the Duke's guards from shooting Elsa with a crossbow by redirecting the bow to the chandelier, which knocked Elsa unconscious.
Hans later asked an imprisoned Elsa to restore summer, but the ice queen revealed she didn't know how to. Soon afterwards, Anna returned to Arendelle and informed Hans that Elsa had struck her with her ice powers, and she will soon freeze solid unless an act of true love reverses the curse. She then asks Hans to kiss her, but he refuses, finally revealing his true plans of ruling Arendelle, and locks Anna in a room before telling the other dignitaries that Elsa killed Anna, and then sentences Elsa to death.
However, Elsa escapes into the fjord, forcing Hans to follow her onto the fjord to kill her. However, Elsa creates a blizzard across Arendelle in her panicked state, which nearly results in the deaths of him, Elsa, Anna and Kristoff. However, he manages to reach her through the snowstorm and tells her that Anna has died due to her, causing Elsa to break down and the blizzard to subside, giving Hans the chance to kill her with his sword. However, an escaped Anna deflects the blow just as she freezes solid, and he is knocked unconscious.
Hans later regains consciousness just as Elsa thaws Arendelle and Anna returns to normal, as her sacrifice for her sister counted as an act of true love. Hans is shocked at this turn of events, but an enraged Anna punches him off the ship they are standing on and causes him to land in the lake. Hans is later shipped back to the Southern Isles to receive punishment form his twelve older brothers.