This was a much more substantial short than 'Rio Adopts a Puppy', twice as long, ten times more interesting and with a bit of character development that links to the greater scope of the series.
This short story is a very good sketch of two very different women learning about one another and becoming friends, or as close as Cas allows other humans. Because I've read other books with Cas, I found seeing this more human, mundane interaction to be quite interesting. Pilar is in character throughout, and her secondary role in the Null Set novel that I just read is fleshed out a bit by knowing about this backstory. Three and a half stars.
Look, if this doesn't make you ship Cas x Pilar, I don't what will.
I read this after I read "Rio Gets a Puppy" and had a total blast - it definitely filled some of the characterization cravings I had been stuck with following Null Set, while still keeping everyone in character. It also provides a solid foundation for those moving on to Critical Point (though I'm not quite sure how this story fits in to the Cas Russell series vs. the Russell's Attic series).
A good solid foray into Cas' mind and relationships. Like all the Russell's Attic stories to date, the ambiguous nature of the world and characters really infuses the story. As an aside, that metaphysical ambiguity everywhere else makes Cas' math super-powers even more freaky and awesome in my mind. Here's this character who is so precise, so rigid in how she views the world she knows what her error bars and uses that to survive - and is constantly bemused because of the chaos of dealing with other people. This story is how some of that chaos comes in and sets Cas off balance. Again.
In a real sense the central character of this story is Pilar - her needs, wants and reactions are driving almost everything in the story, including most of Cas' own reactions. It's fun to see, and never betrays the setting's basic worldview. (I'll leave it up to others to decide whether the setting for these stories is something like the real world or not.)
An engjoyable read, but one that must be read after the first two full novels in the Russell's Attic series for the magnitude of the story to be appreciated.