Since ancient times, portals have been opening on Earth to other worlds, from which guests come. The guests are very different: aggressive and peaceful, possessing a lot of knowledge or not at all capable of communication. What unites them is their magical gift and the inability to go back. Vladimir Seversky is a young archmage and an employee of the Organization that tracks people who get caught. He is the Gatekeeper, the one who greets guests first and must be prepared for anything. His weapons are a bullet and magic, he has five years of training behind him, and has an interesting and very unusual career ahead. But on his first mission, everything went wrong. The guest is dead, and Vladimir has an unusual traveling companion and a whole bunch of problems. And also the feeling that everything is just beginning...