Valhalla was a spacecraft which carried a troupe of opera singers, who were touring their production of Ultragrossegotterdamerung. After the ship malfunctioned mid-flight, with its inhabitants suspended in cryo-pods, it crash-landed on the colony planet Lindis. The ship's on-board rehearsal computer Odin was damaged, and began controlling the surviving performers via their costume helmets. He ordered them to kidnap local colonists and convert them into "Vikings", in order to complete the performance of the opera.
After twenty years of kidnappings, the Tenth Doctor and Bjorn were kidnapped by Odin's performing Vikings they were taken to Valhalla, where they discovered what was happening. During a fight with Thorir, the ship's computers were damaged and Odin's control over the kidnapped colonists was released. However, this damage caused the already-damaged ship to become unsafe, causing the Doctor, Bjorn and the colonists to flee as the ship exploded. (COMIC: Space Vikings! [+]Loading...["Space Vikings! (comic story)"])