The heroine of this story is a simple girl from Odesa named Tonya Chumakova who dreams of the sea. And so she is hired as a radio operator on one of the ships of the Black Sea whaling fleet...

Young musician Zhenya Kovalchuk falls in love with aerobatic pilot Yulia. The feeling is mutual, but Yulia cannot bring herself to reveal her feelings to Zhenya. Then the famous, but not yet elderly, Doctor of Science Kressovsky, who also hopes for Yulia's affection, stands in his way. The two suitors clash with their swords, and the duel ends with the doctor being wounded. The doctor intrigues, and Zhenya faces expulsion from the institute.

A strange phenomenon has been noticed on the outskirts of our Solar system that quickly approaches the Earth. It's called "Orion's Loop." A spaceship with a crew of people and androids identical to them is sent to intercept the anomaly. But strange events start happening as the spaceship approaches the mysterious loop.