The former reputed lover and bon vivant Petr Vok from Rožmberk was widowed at the age of sixty-three. The loss of his much younger wife is hard to bear and it seems that nothing in his life will please him anymore. His loyal friends and servants do everything possible and impossible to cheer him up, but sometimes interesting situations arise, such as when they get him a guaranteed real mermaid. Will anyone be able to cure the master of his lethargy?