A university professor (Henryk Baranowski) trains his young son in the use of reason and the scientific method, but is confronted with the unpredictability of fate.

Irene and Krzysztof discuss Paweł's decision to take religious courses at the local church.

Paweł finds a pair of skates, meant to be a Christmas gift, under the couch, and wants to try them on the lake not far away from their home.

His father gives his permission because the computer tells him the ice will be thick enough to withstand three times the boy's weight.

Krzysztof remains calm at first and refuses to believe that the ice could have broken, since his calculations clearly indicated that this was not possible.

Krzysztof later walks into a provisional church, destroying a small altar to the Black Madonna of Częstochowa, in the process knocking over a candle that drips wax onto the icon's face, making it appear to be crying.