This is a film from the series of so-called "defense" films, which presents a hypothetical "scenario" of a future war. The crew of test pilot Sergei Novikov makes a long non-stop flight on an airplane of a new design. Novikov's son, Yurka, a passionate inventor, manages to contact his father using a transmitter he designed himself. Just before landing Novikov felt bad - an old leg wound, received during the Civil War, had opened. But still the pilot managed to land the plane on the airfield of t...