A group of radio amateurs receives a mysterious signal from an unknown station. Soon one of them disappears under mysterious circumstances.
Then another one.
Postgraduate student of Chernihiv Polytechnic University Bohdan Karpenko.
His sister Hanna goes in search. Mykola, a novice radio amateur, helps her because he liked Hanna at first sight.
But there are secrets in the world, the discover of which will have to pay a high price...