[He steps inside, and it seems he thought the fact he'd be coming empty-handed - and thus made sure he wasn't.]

I've more manners than to promise an appearance, only to not appear.

[He offers Astarion a book, a certain Thayan tome that's been in his possession for long enough.]

Your book. I don't recommend we summon any spirits tonight other than those we'll be drinking, but my studies are elsewhere these days. Should I decide to practice more necromancy in the future, I'll be asking for this again, but for now, it's best kept with your belongings.