Kate is thrilled when her English cousin Beth visits for her twelfth birthday, and they stumble upon a secret in Vendermeer Manor that may bring them closer to unraveling the family mystery that's been hidden away for generations.

It's the end of June in 1914, and Beth Etheridge is traveling from her home in England's Chatswood Manor all the way to America, to visit her cousin Kate at Vandermeer Manor in Rhode Island. The girls are thrilled to be united, especially because Beth will be in attendance when Kate receives the heirloom "Katherine" necklace: one half of a heart encrusted with gorgeous rubies. It's the companion to Beth's "Elizabeth" necklace. But the trip is cut short when news arrives of the assassination of Archduke Franz Ferdinand. With talk of war on the horizon, Beth is ordered to return home, but Kate knows the perfect hiding place to help her stay. A wing of Vandermeer Manor is rumored to be haunted, and as the girls explore, they find a different kind of ghost--and a new trove of family secrets.