Famous motorcycle racer Fyodor Yermolaev was invited to the circus for the "deadly trick": to make a leap on a motorcycle under the dome. His assistant - a quiet gentle Lena (Ludmila Kasatkina) - dreams of becoming a tiger tamer. Their trick has a grandiose success, and Yermolaev falls in love in an unknown modest circus actor. At the same time, the regular tamer-alcoholic is dismissed. The tigers growl and frighten. Lena enters the cage and - after training them, goes to the arena.