A boy and a dog were playing hockey when suddenly the ice broke and started moving. And the faithful dog first of all saved his master, and later died in the hospital. The boy did not know this, and for several days he called the veterinarian, pretending to be either the chief minister or the chief judge of the country, and threatened to write an angry letter to «Pionerskaya Pravda». The cartoon ends with a dramatic scene when the veterinarian brought Seryozha another puppy and informed the boy about Rex's death. For a moment, the boy's whole world turned black. "You really need a friend right now, and so does the puppy." A wonderful touching cartoon with beautiful music by Evgeny Krylatov.