The Shadows (The Books of Elsewhere, #1)

Old Ms. McMartin is definitely dead. Now her crumbling Victorian mansion lies vacant. When eleven-year-old Olive and her dippy mathematician parents move in, she knows there's something odd about the place--not least the walls covered in strange antique paintings. But when Olive finds a pair of old spectacles in a dusty drawer, she discovers the most peculiar thing yet: She can travel inside these paintings to a world that's strangely quiet . . . and eerily like her own. Yet Elsewhere harbors dark secrets--and Morton, an undersized boy with an outsize temper. As she and Morton form an uneasy alliance, Olive finds herself ensnared in a plan darker and more dangerous than she could have imagined, confronting a power that wants to be rid of her by any means necessary. It's up to Olive to save the house from the dark shadows, before the lights go out for good.