Krútňava (abroad staged as The Whirlpool or Katrena after the main female role) is an opera in six scenes by Eugen Suchoň written in the 1940s to a libretto by the composer and Štefan Hoza, based on a novella, Za vyšným mlynom (Beyond the Upper Mill) by Milo Urban.
In 1941 he read Urban's novella Beyond the Upper Mill, a story of love and murder set in the Slovak countryside in the years after World War I, which immediately inspired him.
Urban himself however refused to collaborate on the libretto, writing in 1958 that the dramatization risked losing some of the ambiguities he had deliberately created in the book (e.g. the paternity of the heroine's baby).
Although the premiere was successful, the governing Slovak Communist Party insisted that the original ending be changed to make it more 'optimistic'.
Other serious changes were forced on the composer, involving dismantling the very important 'framework' to the opera which posited the story as the result of a wager between the Poet and his Double (spoken roles), and, inevitably, the toning down of any references to Christianity.
Pressure from his musical colleagues, who realised the importance of the work, induced him to change his mind, and this 'revised version' was performed in Czechoslovakia and abroad in the 1950s, the original ending only being restored in 1963.
In the original version, the Double tries to persuade him (in an unusual duet between tenor and spoken voice) that there is no point in giving himself up as no-one knows about the crime; however Ondrej resists this temptation.
In the original version Old Štelina is reconciled to the situation and shows that his concern is to assist Katrena to bring up the child.