Origin, by JA Konrath

This is a weird one: the US government is hiding Satan (for lack of a better descriptor) in an underground bunker in New Mexico (why is it always New Mexico for these things?). Our hero is a polyglot linguist, drafted to interpret the monster's language as he wakes up.

What really bothered me about this was the plot line that has the featured characters prioritize their own sorry lives above the betterment of humanity - I like my heroes to be heroic, not pathetic. And that it is set up for a sequel. Which I won't read even if offered, as this one was, at 99 cents.