Through Saturday, The Fortuitous Meeting, by Christopher Kastensmidt, is free to download from Amazon:
http://www.amazon.com/Fortuitous-Mee...dp/B00YLQONBQ/
This particular edition has been self-published by the author, but the novelette appeared originally in Realms of Fantasy and was a finalist for the 2010 Nebula Award.
I highly recommend this story (in case someone is interested, I reviewed together with the other two novelettes in the series:
http://sentidodelamaravilla.blogspot...banner-by.html )