Caesar is the name of the dog with which a little boy, only seven years old, sets out on a great quest to find his mother. She once gave him the dog before she emigrated. The boy does not agree with his father's intentions to remarry, even though the new mother is supposed to be a sympathetic governess from a children's sanatorium. The film was made at the very end of the former regime, but it was not released until the changed political situation.

Little boy considers to have discovered traces of the aliens but in fact comes across the activity of small thieves.

No one has ever managed to enter the dark cave of the fairy Asteria twice. Anyone brought here by chance or curiosity has been petrified. Only the brave Tomas was able to convince the fairy that his anger was mostly self-inflicted. In the end, it wasn't even that hard. It was enough to awaken the feeling of love in Asteria.