At the end of the 22nd century Alisa Seleznyova, her father Professor Seleznyov and pilot Zelyony go on a space expedition to find rare animals for Moscow Zoo. On the way they seem to encounter a mysterious conspiracy led by Doctor Verhovtsev against legendary Two Captains Kim and Buran. The only clue is a talking bird Сhatterer [Govorun] that our heroes accidentally took possession of.
Children end up in Ancient Greece, where they learn the laws of physics from Archimedes.
Two aliens are landing on the earth. One looks like a Bigfoot, the other has the appearance of a tiger. The problem is that they landed one in the USSR, the other in India. Soviet pioneers help them meet.
