The best way to teach someone to swim is to push them into the water. Some people think so. And the best way to test newcomers in action is to send them to an underwater city attacked by gremlins. This is the opinion of the Professor, the famous hero of the Base, who suddenly discovered his teaching talents. At his suggestion, a young task force is sent to work: a militant, two techno-mages and an engineer. True, the techno-mages are beginners, the fighter is too warlike, and the engineer is just a kitten, but, according to the experience of the elders, the presence of talking animals in the group only adds fun and adventure!