On 5 June 1944, the allies liberated Rome, and the following day, D-Day, marked the beginning of the liberation of western Europe and the onset of Hitler's downfall. On 25 August, Paris was liberated, followed by Brussels in early September. The Russians continued pushing westwards, having discovered the horrors of the Majdenek extermination camp in July, followed by Belzec, Sobibór and Treblinka soon after. With Germany facing military and economic collapse, Hitler's power was waning. The most famous of the plots to assassinate Hitler, masterminded by Claus von Stauffenberg in July, was, alas, unsuccessful. Yet, although the Germans now knew they faced inevitable defeat, and though they had begun to try and destroy the evidence of the Holocaust, the genocide continued.

In Terezín, Viktor Ullmann had been working on The Emperor of Atlantis with his librettist Petr Kien. This one-act opera, with its subtitle ‘Death Abdicates’, is an obvious allegory on Hitler's despotic rule, and although there is no evidence that any of the SS witnessed the rehearsals, the Council of Elders felt uneasy with this aspect and feared reprisals. The bass singer and former prisoner Karel Berman, for whom Ullmann wrote the character of Death in the opera, and the only member of the cast to have survived, stated that the opera ‘was prohibited before it was ever performed’: the symbolic nature of the work was felt to be too close to reality to call. It is uncertain how far the rehearsals progressed, but as the production was not ready by September, the final transports would in any event have put paid to a public performance.

The composition that Klein was working on at that time is also replete with symbolism – which, of course, it is far easier to conceal in a wordless instrumental work than in a stage work. The Trio for Violin, Viola and Cello was completed on 7 October 1944, thus forming a trio of outstanding works for string trio, along with Hans Krása's Tanec and the Passacaglia and Fugue, also composed in 1944. The final transports had not commenced by the time Klein's first two movements were completed, and so high-quality string-players were still available in the camp.