In a wooden hut used as a canvassing center, members of a children's puppet-theatre group are rehearsing for a production about a journey to the Moon. The goings-on inside the hut and outside are being closely followed by amateur detective Pepik Barnabás. He, however, is the first to be under suspicion when a trunk containing puppets goes missing. The children follow him but, when they catch up with him, they discover he hasn't got it. Pepík offers to help them in their search.

On an early Sunday evening, people of the small town are reading lottery results that are hung on a board. Young man Karel Antos is annoyed that his lottery-ticket missed the main prize, a car, by only one number. Karel is going to the pub to drink away his bad luck with his friend Jirka Broz. The old accountant auditor Zelinka drops a wallet. Karel picks it up and before he gives it back he notices the winning lottery-ticket in it. Both young men accompany the old drunk man. Karel steals the ticket and exchanges it with his own. Next day, Zelinka is found dead. Investigators, Captain Tuma and the Lieutenant Líbal, soon discover that this is a murder case covered up as an accident.

Czech friends help refugees from Nazi Germany escape in 1939.