Cora Bender's measured, calm life ended after Christmas: every Friday and Saturday, when her husband comes to her bed, the same song rumbles in Cora's head, which drives her crazy... One day, unable to contain her madness, she almost broke her husband's neck. In order to somehow improve relations, the family goes on vacation to the lake. Cora is contemplating suicide, but before that she wants to spend a little more time with her little son. However, even there Cora lost control of herself. She used a knife to kill a man who happened to be next to her on the beach... It was all because of the unfortunate song...