When stranded in her partner’s old ski village on the anniversary of his disappearance, a distraught woman must finally kill the old thing that’s been lurking in the snow.

I'd personally drop the when and reword the star more like, "Stranded on the anniversary of her partner's disappearance in his old ski village..." To me that comes right out the gate with impact, of course this is a personal preference. Did her partner own a ski village or live there or was it a place he visited? The wording for that seems a tad off to me, maybe I'm not versed enough in skiing to understand that. Still, I would be interested to know what has been lurking in the snow.