An old shipwrecked sailor is the accomplice and bait for a group of pirates, who use the tempting prospect of a fabulous treasure to lure sailors in order to seize their riches more easily. Our Vikings fall into the trap, but Vic and Ulme use their talents as puppeteers to scare the brigands of the seas and send them packing.
Halvar, his men and the drakkar are kidnapped by Sven! In order to catch up with them, Vic whips up some kite-surfing gear with a board and burlap bags. With Snorre and Tjure, he manages to get his father's drakkar back. Since the sail is ripped, Vic has the idea of making it move by building two large paddle wheels built with the help of Tjure, the crew's carpenter, and Snorre. Astounded by this boat with wheels, Sven's men take their eyes off of their prisoners and don't see Vic climb on board and cut the prisoners' ropes. The prisoners take the opportunity to attack and Vic helps them imprison their kidnappers by trapping them in the middle of the paddle wheels.
In order to scare away tax collectors sent by Eric the Greedy, Vic invents a magic lantern (from flat pieces of translucent stones painted by Ulme and mirrors that focus the sun's light). He uses this to project "monsters" at the entrance to a cave (where the villagers have hidden all their wealth), frightening the tax collectors away.
Each year, our brave Vikings have to plough the field so they can have enough vegetables and cereal. Unfortunately, Halvar is not ready to do so and rather like to go pillaging. Women are not happy and have blocked the drakkar on shore. Vic tries to plough the field with the drakkar's anchor but it stays stuck in the ground. He discovers the forgotten treasure of Flake hidden between some roots. Vic sows coins in the field so the Vikings have now a great pleasure ploughing! Ylva's happy and lets his husband go pillaging for Vic's relief.
Halvar and his men discover a mysterious cavern where Sven and his pirates hide their loot. This cavern has kept all the words Sven and his men exchanged during the last winter. When the pirates arrive to the cavern, the clever Vikings pretend to be invisible and with the words released from their frozen bubbles, the pirates soon get scared. Halvar can have his loot back!
Halvar's treasure-loaded ship is robbed by Sven's pirates. Vic thinks up a way to lure his ship to a dangerous cliff by dressing up Tjure as a mermaid.
