Pierre and Catou Brunet are two young orphans from Chicoutimi and faithful fans of the Montreal Canadiens Hockey Club. One day Pierre accidentally overhears a plot to smuggle diamonds into the United States by hiding them inside a hockey puck and slipping it into the Montreal Canadiens’ equipment. Pierre immediately tries to tell what he has overheard, but no one believes him. He realizes that he must warn the Canadiens Hockey Club. And the chase is on as the bumbling smugglers, Napoleon and Belletête, try to prevent Pierre and his sister from exposing their plans.
The chase gets underway in Chicoutimi where the kids stow away in the smugglers’ flower truck. On the way to Quebec City, they are discovered but manage to escape into the woods. There they are aided by a bush pilot and his rattle trap plane. With the smugglers hot on their heels, he whisks the kids out of danger and flies them to Quebec City.
In Quebec, the kids manage to get hold of the diamond-filled puck only seconds before the smugglers arrive. The chase continues across the ice-filled St. Lawrence River, up the cliffs of the Citadel and through the crowded streets of Quebec at Carnival time. One step ahead of the smugglers, the kids head for Montreal. They are taken in by a kind old lady who offers them a lift, but as we soon discover, has other plans for them. The two orphans find themselves prisoners in an old French Canadian chateau. The puck is now in the hands of the old lady who is in reality the boss of the smugglers. After a daring escape from the chateau and many other misadventures and close calls, Pierre and Catou finally arrive in the Montreal Forum where a hockey game is in progress. Napoleon, Belletête, the old lady and her chauffeur are all there. What ensues is a suspenseful pursuit of Pierre by the chauffeur on the catwalks high above the ice and a hilarious denouement as the smugglers scramble for the puck on the ice. The Canadiens win, the smugglers are captured and Pierre and Catou are heroes.
Pierre et Catou sont des orphelins de Chicoutimi qui ont une véritable passion pour le hockey et leur équipe favorite, les Canadiens de Montréal. Un jour, Pierre découvre que des malfaiteurs veulent passer des diamants aux États-Unis en les camouflant dans une rondelle de l’équipe. Personne autour de Pierre ne veut le croire. Avec sa soeur Catou, il décide de sauver la réputation de ses idoles. Commence alors une poursuite trépidante entre les enfants et les bandits. C’est ainsi qu’ils se retrouvent à Québec en plein carnaval d’hiver et enfin à Montréal où les Canadiens disputent un match important. À la troisième période, la rondelle aux diamants est mise au jeu. Pierre et Catou pourront-ils sauvegarder l’image glorieuse et sans reproche des joueurs du Canadien?