Christopher some time ago found an ancient Roman ring with an image of a phoenix on the banks of the Thames, which took him back to 1666, during the Great Fire of London! Christopher was not only able to resist the crazy medieval fanatics, but also managed to make friends. And now, having returned to his time, he wants to see them again. However, this time the ring took him back to the times of... the Vikings! Christopher found himself in the camp of powerful warriors who believed that this strangely dressed boy was either an enemy spy or... a river spirit. The Viking leader Hildr Langswerd does not intend to let him go. But who knows, maybe the mighty warrior is not at all what he seems...