Chain reaction from the achievement of the critical mass, develops uncontrollably and without the need of participation of an initiating factor. It is impossible to stop, just like the one which caused the outburst of the Chernobyl power station in 1986. Marta and her fiancée Adam are planning their wedding. Their friend Pawe? has just finished a film school. One of them has already made an irreversible choice which will lead to a reaction after which nothing will be like it used to be.