Second half of the sixteenth century. Livonian War. The troops of Ivan the Terrible's ally, Prince Magnus of Livonia, besieged Revel. Cores and bullets whistle, dashing infantry drags assault ladders... and no one realizes that the prince himself is not real! And our contemporary, who turned out to be in the past of his own free will, Leonid Artsybashev. In Moscow, Leonid discovered in one of the antique shops an old manuscript of the era of Ivan the Terrible. After following the owner of the manuscript, Leonid ended up in the dungeons of Moscow... from where he got out into the basement of the Tainitskaya Tower of the Kremlin in the sixteenth century, just during the reign of Tsar Ivan Vasilyevich. Strangely dressed Artsybashev is mistaken for a "Danish German" - Ivan's ally, the Livonian prince Magnus. Meanwhile, the course connecting the era has closed, but our hero is not going to give up just like that: you need to somehow survive and get out.