The Watcher in the Shadows by Carlos Ruiz Zafón
My rating: 4 of 5 stars
This is definitely on par with The Midnight Palace (for some reason, Prince of Mist didn't do it for me).
Irene, her mother Simone and brother Dorian leave Paris to move to Normandy; Simone has taken a job working as a housekeeper for an engineer/inventor named Lazarus Jann. Hannah, the maid, conveys all the town gossip and tells the tale of the disappearance of Alma; Ismael, Irene's soon-to-be boyfriend, has Alma's diary. One dark and stormy night, Hannah finds herself in a room she's never been in before, and is somehow convinced to uncork a small flask - a dark shadow escapes.
This is definitely not a just before bedtime read: the evil of the shadow, the various automatons, the question of what happened to Alma, and the house are all written with an eye towards creating that shivver that won't quit. The pacing was a little odd at times, but younger readers may not notice. The epilogue could have been done without, but it does give some closure to Irene's story.
ARC provided by publisher.