Hannah Jordan lives in a museum...well, sort of. She is the daughter of the caretaker for mansion-turned-museum The Elms in Newport, Rhode Island. Hannah's captivated by stories of The Elms's original occupants, especially Maggie Dunlap, the tween heiress subject of a painting that went missing during a legendary art heist in 1905.

But when a mysterious mirror allows Hannah and Maggie to switch places in time, suddenly Hannah is racing to stop the heist from happening, while Maggie gets an introduction to iPhones, soccer (which girls can play!), and freedoms like exploring without supervision. Not to mention the best invention of all: sweatpants (so long, corsets!).

As the hours tick away toward the art heist, something's not adding up. Can the girls work together against time--and across it--to set things right? Or will their temporary swap become a permanent trade?