Very well written. Definitely horror and not romance. The sex scene was probably the least hot sex scene I've ever read (between two consenting adults). I could have done without it.
World is well built but truly horrific and chilling. Distances were confusing. Mac could see stuff coming in too much detail for how long it took to arrive.
Ambiguous ending typical of horror but I hate it in a romance.
2 stars for enjoyment, 4.5 stars for storytelling makes it a 3.5 star read for me, rounded up because it did a lot for a short story.