It all begins underwater where Harold and his Uncle Mayor is searching a meteor fragment. Mayor Humdinger noticed it but Harold steals it. Mayor Humdinger then swims after him.
At the Lookout the pups are playing at the yard and Ryder shows up with Everest. Rubble tells her that she is right on time to pick a game and she suggests, and the others replied "freeze tag". Chase is "it" tagging Marshall. Unbeknowest to them, Harold arrived and spied on them giving an evil idea how to wreck havoc Adventure Bay.
At Foggy Bottom Lair, Harold Humdinger constructed a Freeze-ray and stabs Mayor Humdinger in the back by freezing him and heads for Adventure Bay. At the docks Cap'n Turbot is giving a treat to Wally until Harold freeze them. Francois assumed they are playing until he decides to call the PAW Patrol. Harold then freezes Danny and Mr. Porter. Alex calls the PAW Patrol along with Francois telling them the situation and the mighty pups are on the way. The pups gets their powers again as the Mighty Lookout is transformed. Ryder briefs the Mighty Pups and tells them the situation. He orders Skye to find and stop Harold while Marshall uses his heat paws to unfreeze the frozen citizens and they deploy.
Marshall along with Ryder heads to the docks and unfreezes the Turbots. At City Hall Mayor Goodway is helplessly ranting at Harold. But Harold did not listen and Skye noticed. Harold fires but Skye missed. Marshall managed to unfreeze Danny and Mr. Porter. Mr. Porter gives Ryder and Idea to contact Everest. Skye tells Ryder that Harold is going for the train station While Marshall heads for City Hall to unfreeze Mayor Goodway.
Skye and Harold are having a duel in the skies. Harold Managed to freeze Mr. Hudson and Skye crashes due to freezing and Marshall jumps on Ryder back and managed to unfreeze and recover Skye causing a 2 on 1 fight. Skye warns Ryder and Marshall to avoid the ice blast. Ryder commands Everest to freeze Harold. Everest used her freeze breath to freeze Harold and his vehicle. Harold complains hypocritically that freezing people is not nice. Harold ejects and then laments in defeat that he lost the meteor piece, his super powers and his vehicle. The vehicle and the meteor fragment are sinking down back into the bay.
The train is disconnected from the track and heads into the bay causing Everest to make an ice ramp and the train jumps over the town and Ryder orders Robo-Dog to use the Mighty Jet's tractor beam to stop the train. And they return the train to the rails and Marshall unfreezed the train engineer.
Mayor Goodway thanks Ryder and the Mighty Pups for warming the town and their hearts. The Kitten Catastrophe crew are busy unfreezing Mayor Humdinger, who asked where Harold is. And Harold landed in the south pole and tells himself that he doesn't even like feeling cold.