Canto III opens with Spidala hurrying to the hut of Kangars to warn him that Bearslayer was present in the Devil's Pit and saw the shameful deeds. To prevent Bearslayer revealing that he and Spidala are in league with the Devil, Kangars decides to lure the young hero into a trap by provoking a war against the Estonian Giant, Kalapuisis, certain that Bearslayer will rush into battle against the invincible foeman and be killed. As Kangars explains this plot to Spidala a terrible storm arises, and Spidala is unable to return home. The storm was sent by Perkons to destroy a ship just arriving at the mouth of the River Daugava from Germany, in order to kill the German missionaries it is carrying. Led by the priest, Dietrich, they have come with the intention of forcing the Baltic people to accept Christianity. However, the Livian fisher-folk of the Daugava estuary rescue the passengers from the ship. Thus, they thwart the will of Perkons, who had planned to drown the newcomers, and save the very people who will eventually become their conquerors. The morning after the storm, a fisherman brings Dietrich to Kangars, and an alliance is forged, since both want to introduce Christianity, although for differing reasons. Years pass. Bearslayer and Koknesis study hard in the Castle of Burtnieks. Bearslayer has a special reason to seek perfection: Laimdota is the daughter of Burtnieks and has returned home to the castle from Staburadze's Crystal Palace, where she and Bearslayer met. They fall in love, but just as Bearslayer is about to ask for her hand news arrives that Kalapuisis has entered Latvia and is killing and laying waste. Burtnieks offers Laimdota's hand to any warrior who can rid them of Kalapuisis, and Bearslayer rides out to face him: The plot seems to be succeeding! Bearslayer faces Kalapuisis in single combat, and defeats him. However, just as Bearslayer is about to kill him, Kalapuisis reveals a prophecy told him by his mother that a bear cub from the Daugava, who is of noble rank and equal to Kalapuisis as a warrior, will come and save the Latvians from their conquerors. The two warriors realize that Bearslayer is this bear cub, and that they have a common enemy-the Germans-and make peace, so that they can work together against the invaders. Successful in the Estonian war, Bearslayer returns to Burtnieks's Castle with the other Latvian warriors, and they are greeted in song by the local maidens. Laimdota places an oak-leaf wreath on Bearslayer's head and sings of his might, promising to make him a true and virtuous wife. Bearslayer replies in song that he will live and die for Laimdota. Amid great joy and feelings of brotherhood the warriors toast Bearslayer, and conclude that the gods personally intervened on his behalf. This divine intervention gives Bearslayer legendary status so that, instead of destroying him, the plot added to his fame.