I think my biggest comment here is that the characters seem a little emotionally detached. Irving, I get. He's got clear motivation, and I can feel the emotional hooks, but Stephanie seems a little blase about coming face to face with a surrogate father who's betrayed her and is now using her summon the devil, and from this chapter alone, not having read the others, I really don't have a sense of Renfield. This might just be the effect of coming in late, but I thought I'd mention it.