This isn't a sequel to Frank Borzage's Three Comrades made a year earlier, but it follows on from its historical timeline, as the Nazis come to power in Germany. Margaret Sullavan returns to star. Both films are set in a similarly artificial studio recreation of middle Europe. The most significant change is that this film names the Nazis, and portrays them as a threat to humanity.
Which makes this a landmark Hollywood film, and of course it was banned in Germany. The narrative starts with the news that Hitler has become Chancellor. Instantly, the population of this small, idyllic Alpine town becomes infected by hostility. It's like a disease that passes through the community. The aura of threat is appalling.
Though a drama, this is one of the great horror films of the decade. The people are possessed by militarism, populism and racial hatred. Those who are immune have no one they can trust. Every stranger is a threat. Eventually Sullavan and James Stewart, flee over the Alps to seek refuge. Robert Young as their former friend turned Nazi is extraordinarily ominous in their pursuit.
It's a Borzage film, so this is about the primal, transcendent nature of love. Humanity is the mortal storm. Stewart and the ethereal, agonised Sullavan as the lovers caught up in its turbulence are pitifully moving. The film doesn't attempt to suggest reasons for the rise of the Nazis, because there is no justification for the madness. It mattered because Hollywood, and MGM, had taken a side.