July, 1937. A young missionaries daughter must evade the wrath of a merciless NKVD Major, and flee for her life through anti christian Soviet Union before the harsh winter sets in.

When a young nun refuses the advance of a merciless major in the feared NKVD secret police force, she flees the transiberian express and must survive her journey to Russia Far East before the harsh winter sets in.

The logline doesn't paint a clear image of the obstacle, main action and a tangible goal. I think it is because the logic of the premise is hard to understand.

I know the soviet union was harsh on religion but I wasn't aware of significant anti christian tendencies even in it's idealistic early days.
Even if this was the case a logline should be able to paint a clear picture to anyone that hears it without the need for them to do any research about the subject matter.

Perhaps try to focus on the obstacles, antagonist and a tangible goal rather than the environment and social/political movements.

Tried a stab at it my self:
1937, with a few weeks of Autumn left, when a girl's missionary parents are killed by a merciless major gone mad the young introverted girl must flee from Moscow to Bern to avoid being captured and save her own life.

What's the inciting incident? That is, what did the girl do to arouse the officer's wrath?