I've just started reading Bram Stoker's Dracula to Serafina (and Lynn who takes to listening in sometimes). We're only 20 pages in. It's very significant reading. The vocabulary is immense, the sentence structure is complicated, and the imagery is astounding. And Serafina is engaged. It helps that she played "The Child" in a stage version of Dracula (with Cuesta College Theater Dept, last October, see some pics), and that makes for interesting discussions comparing the original writing to the play. I haven't read anything as demanding in a very long time; loving it.
Be warned: there are significant adult themes and horrifying (imagine that, in a horror story!) descriptions of sexual predators and mental illness. Not for the faint of heart, and not for any-aged person who doesn't have a basic grip on the world. Fortunately, it's never explicit (IMO), everything is done with imagery, leaving the mind to fill in the blanks as it can. Your mileage may vary. The lowest age I saw mentioned as appropriate was 8th grade, and some suggested "adults only".
When we get done, I'll come back and update this post with any additional thoughts I may have about the experience of reading this with a well-grounded 4th grader.