Archaeologist Sigurd Svendsen discovers that the Oseberg ship hides a secret from the Viking Age. Along with his two children put Sigurd out on a quest to find the truth. The mystery leads them into "No Man's Land" between Norway and Russia where no man traveling in modern times. Old runes take on new meaning when the secret they uncover is more frightening than anyone could have imagined.

Thor is imprisoned on the other side of the universe and finds himself in a race against time to get back to Asgard to stop Ragnarok, the destruction of his home-world and the end of Asgardian civilization, at the hands of a powerful new threat, the ruthless Hela.

故事发生在一间名为“燕雀”的侦探社之中，坐镇其中的，是名为洛基（樱井孝宏 配音）的美少年侦探。虽然表面上看来只是一个小孩子，但洛基的真身其实是北欧神话中的邪神，因为作恶多端而被放逐人间，在此期间陪伴着洛基，照料他饮食起居的，是原型为一条巨蟒的暗野龙介（三木真一郎 配音）。　　一次偶然中，一个名为大堂寺茧良（堀江由衣 配音）在无意之间闯入了燕雀侦探社之中，她希望洛基能够帮助她替一个会说话的洋娃娃找到曾经的主人。一番波折之后，事件总算顺利解决，而在此之后，茧良竟然自说自话地成为了洛基的助手，两人一同面对的，是各式各样科学难以解释的灵异事件。