Good, but I'm wondering what it was he gave up in exchange for those extra ten minutes. Also, did he kill her? I like the twist of the faulty contract, and you have excellent writing skills, but how the plot ends doesn't seem, enough. Try elaborating on what he hopes to gain from the agreement with the old man, maybe make the contract more complicated and add a loophole to make it more surprising when it proves faulty. I'd also try making the end more horrific. I was expecting this to turn out more like The Monkey's Paw though when I first started reading, so I could be biased. =P

Wow, this is a really creepy story! I love the description. I'm still not really clear on what happens at the end, though, and what the italicized parts mean. Maybe I'm just slow...^^ I'll go read it over again.

In the meantime, here's some cc:

I think in the first paragraph you mean "the boughs *that* pull at his hair..." Also, in the end of the second italicized part you have "and does move again for a long time" - did you mean "doesn't"? Otherwise it sounds a bit awkward.

The whole of paragraph 17 feels weird. I think "explained" is the wrong word - maybe "announced" would be better. Also, "reaching for the hand Mary had extended as he passed behind her" sounds awkward.

In p.29, you have "Why don’t I take your place for a few hours while you [...] rest for a moment?" that's a contradiction. I mean, it could just be the character making a mistake, but I think it's more confusing than anything else.

In p.32, I think you overuse the word "try"

In p. 35, what do you mean by "his phrasing"? I don't see anything unusual withwhat he said or how he phrased it.

p. 58: "cold and ancient joy" - I love this phrase! ^^

This was really confusing. I didn't get it at first, but now I do. This was a good story. I think that maybe you could publish it. It's very interesting. I think that it would be good to add a little more to the story. But that's just my opinion. This turned out really well. Good luck, and keep writing!