[ Astarion has such a way of seeming like he doesn't care at all, like this is nothing to him. For Gale, who cares far too much about everything all the time, it's impossible to imagine ever being that way. He certainly would have remembered exactly where he found the book. ]

Ah, [ he says, knowingly. Theft. ] Your misappropriation is greatly appreciated! Well, by me, at least. I imagine someone is sorely missing this.

[ He would be heartbroken if someone stole something like this from him — and yet his tone shows little empathy for the grimoire's former owner. Whatever sorry soul Astarion took a souvenir from, it's Gale's now. Difficult to get bogged down in morality when Astarion's misdeeds have produced such an exciting prize. Besides, it's not as if he can return it now.

Gale takes a moment, deep in thought, then says, ] I suppose I could offer more than my gratitude, if you were interested. I couldn't help but notice you're quite the reader yourself.

[ At least, if how he spends his time in camp is any indication. He can't imagine Astarion's taste in literature, but whatever it is, Gale's certain it could be improved with his input (as could all things). ]

Perhaps you might like to borrow something. I've a veritable cornucopia of excellent literary taste.