Thanks to LTU for emailing me this while the site was down :
"He had been unable . . ." - Should be fixed. That "had been," is like a big rock to trip over.
In fact you seem to use "had," a lot. I recommend you find a better way to say things without resorting to that word.
One of the things about this story is how much I'm expecting something grander then "I've got to find the book." That, is all honesty, is probably me just wanting things to be bigger. But then . . . your story spends a lot of time wondering the plot of "find the book, save the boy." It feels like there is a major climax coming now that he's aware the book is still in the library. Because I don't think the whole thing is going to be ten chapters or whatever, I am sitting and expecting something much bigger to come out. And that expectation is leaving me a little impatient.
Now "slow" does not mean boring. I'm not saying the piece is slow. I, personally, feel like I'm just waiting for something to happen. Your story seems very plot driven at the moment. Not a bad thing, please don't misunderstand. It is because it is plot driven that I have the above expectation. Like something is going to explode and everything is going to go really really really really really wrong. And that anticipation is both enticing and annoying. I feel inclined to read more, but I feel cheated at the same time because the carrot in front of my face keeps moving.