A young engineer Dmitriy Zherekhov who came to the aircraft plant is trying to prove to the director that it is necessary to switch to new methods of organizing production. He is supported by both experienced test engineer Aleksei Sedykh and test engineer Lyudmila Rudneva. Lyudmila likes Dmitriy, but his rigidity and rationalism complicate their relationship...
An ancient blade with diamonds is stolen from the museum where Alexei Gurov works as a restorer. Soon an old icon is stolen from Gurov's apartment. Head of the crime investigation is the police colonel Georgy Arefyev. Everyone knows that Gurov is obsessed with collecting rarities, so suspicion falls heavy on him.