A year after Gerda Ronja Mannov Olesen defeated the Snow Queen, Orm the anteater-like troll wakes up the rest of his kin and now lives with his grandmother Esther Knudsen Rosa and Gerda’s pet white ferret Luta, working in the troll village as a miner. He swears an oath at Lake Gao never to tell another lie, and from that moment his reflection comes to life and begins to twist him toward misdeeds, including lying.
After being fired from his job for insulting the knight Arrog and facing eviction from his cottage, Orm is manipulated by his reflection into donning armor so he can take part in a competition to decide who will marry Princess Maribel. In order to impress the Princess and her uncle, the King, Orm lies about defeating the Snow Queen. Meanwhile, Gerda, who has arrived in the village with her brother Kai and friend Alfida, overhears Orm’s lies, sparking a heated argument that drives Gerda away.
Later, as Orm and Rosa move toward the King’s palace, the King says he feels as if he has seen Rosa before, and she wonders if she has changed that much over the years. The North Wind appears and abducts Princess Maribel, prompting the King to decree that whoever rescues her will marry her. Orm, joined by Arrog and the other warriors, sets off to rescue the Princess, but Orm reluctantly abandons the others and arrives at Gerda’s village, only to discover that her mirror has been stolen. Orm then sends Gerda a message asking her to meet him at the Black Cliffs. En route, Gerda, Kai and Alfida meet the trolls, who reveal that Orm had abandoned the troop. Gerda, disillusioned with Orm, sails off with the others, tearfully abandoning Orm at the cliffs.
A distraught Orm is manipulated by his, now blue and frosty, reflection into pulling him into the real world, upon which he freezes the ocean, trapping Gerda and the others. After a confrontation between the two, Orm’s reflection—referring to himself as the “Snow King”—reveals that the more he grows in power, the more Orm weakens and becomes invisible. The Snow King then unleashes his army and overwhelms Orm’s friends, encasing them all in ice. Orm tries to warn Gerda but she can’t see, hear or touch him, and the Snow King tricks her into thinking he is the real Orm and freezes her, and Luta, then traps Orm in the mirror realm. Orm, while trapped, realizes that the Snow King was born from his lies, and manages to free himself by loudly confessing to his lies, thawing out Gerda and the Snow King’s other victims, while at the same time reversing the Snow King back to his normal reflection.
In the end, Orm is taken back to the troll village but, instead of being punished, he is hailed a hero. Rosa marries the King, and Orm gets his cottage back and rekindles his friendship with Gerda. Arrog marries the Princess and have children, as seen during the end credits.
