In an abandoned mine in central Sweden, an amateur diver finds the body of a man who died at least a hundred years ago. In his hand, the dead man convulsively clutches a cross in the shape of the Egyptian hieroglyph Ankh. With this death, the story of the search for a mysterious key begins, allowing one to find the entrance to the underworld, which contains the whole truth about the world order. Historian Don Titelman, accidentally involved in this story, begins his own investigation. The search for the Egyptian star Seb, the missing part of the coveted key, leads him to the very heart of the Arctic in the footsteps of the lost expedition of Nils Strindberg. Will he, after going through many dangerous adventures, be able to get to the bottom of the truth?