I love this. It's very atmospheric; you use language so well to describe not just the physical nature of the scene, but the nuances of feeling it evokes.

Sometimes pre-show Torchwood fics stress me out, but here you've made these original characters incredibly real and believable, and I think your Jack is spot-on. :)

And this:
The snow fell and night drew in and two quite alien worlds brushed feather-light against one another, the inhabitants of each at the very limits of their endurance.

is such a great and dreamy way to end--though the story is from Penny's point of view, the mystery and the silence really seem to add depths to Jack's character as he both fits in so well with his team and yet tries to describe and remember places so far away in time and space.

Awesome story.