The Gang heads up to Canada for a fishing trip with Velma's Uncle John, but they soon discover that he was kidnapped by ghost Vikings. Seeking to find her uncle, Velma and the Gang investigate.
This episode includes examples of the following tropes:
- Artistic License – Animal Care: In the begining of the episode, Scooby decides to eat Shaggy's frozen hot chocolate, and is perfectly fine, when chocolate is toxic to dogs in real life.
- Artistic License – History: Real life Vikings did not really wear helmets with horns on them, it is actually a common myth.
- Chekhov's Gunman: The two geologists that went missing prior the events of the episode, as it turned out that they were two of the Viking Ghosts that were helping Mr. Hansen steal uranium ore.
- Eek, a Mouse!!: When Fred and the girls a looking for the switch for a secret passage at dead end of a tunnel, Daphne discovers a mouse hole, then a mouse comes and scares her, causing Daphne to jump accidentally trigger the switch.
- Fishing Episode: Uncle John invited the gang up to Canada to go fishing for the episode. After the mystery is solved and uncle John is rescued, they get on with the fishing trip at the end of the episode.
- He Knows Too Much: When Uncle John caught the villains in stealing the uranium ore, they had to kidnap him and lock him in a cage to keep him from ruining their scheme.
- Offscreen Moment of Awesome: Somehow before the events of the episode, Uncle John managed discover the uranium ore smuggling scheme that Mr. Hansen and the two geologists were doing. This is the reason they had kidnap him.
- Red Eyes, Take Warning: All three of the Ghost Vikings have red eyes to show they are the villains this episode.
- Tempting Fate: While Shaggy and Scooby are along the lake, Shaggy mentions they are fortunate because the two of them haven’t seen, smelled, or heard anything. Then the the Viking Ghosts' ship appears.
- Where the Hell Is Springfield?: It is never revealed where in Canada that Viking Lake, where the episode takes, is set in. Mostly like in the Canadian province of Newfoundland and Labrador, as it was only the place in North America where Vikings had a settlement, one called Vinland.
