By Christina Askounis.
I found this after reading her short story "The Novice" online. (I found it through Mir.)
It might be bad that the first comparison that comes to mind is to A Wrinkle in Time. Let's see, an evil shadow that's spreading through the universe? Check. A pseudo-scientific method of traveling to other planets? Check. Mysterious old lady who likes to quote Latin aphorisms before disappearing? Check. You get the idea...
That said, the writing seems pretty solid. I noticed that she does a good job of describing the settings and characters, although some are a little cliched, especially the villain. The plot is fairly straightforward, without any of the nasty surprises I've come to expect from authors, but it does have a few twists. It does transparently reference Christianity, with the 23rd Psalm and at least one line from a hymn making an appearance, but even so the characters are not perfect.
In the end, I may have enjoyed this most for the nostalgia factor. The original plan was for it to be the first book in a trilogy, but that seems to be on hold for now.