Fablehaven

Siblings Kendra and Seth go to stay at their grandparents' isolated estate expecting an ordinary visit and instead find the property is a hidden sanctuary for magical creatures, ranging from small, mischievous fairies up to things considerably more dangerous. Brandon Mull builds the book around the two kids gradually learning that their own family is responsible for keeping this preserve of old magic safe, turning an ordinary visit to grandma's into something with much higher stakes. At 384 pages and aimed at ages 6 to 10, it's a meatier fantasy than a lot of what's marketed to that age group, though the grandparents'-house framing keeps it grounded in something familiar.

Kendra and Seth are drawn with genuinely different temperaments — she's the cautious one, he's the one who acts first — and Mull uses that gap to show two equally valid ways of handling danger, rather than making one sibling simply right and the other wrong. As the two dig into the estate's secrets, the conflict between magical factions escalates around them, and the book folds in real ideas about responsibility and looking after something fragile without turning preachy. A strong pick for a kid who wants a fantasy adventure that starts in a believable, ordinary place before the rules of the world expand underneath them.