SPIDERWICK IV, EL ARBOL METALICO (Spiderwick Las Cronicas (Spanish))

The Grace kids, twins Simon and Jared, and Mallory might think that things have finally quieted down for them, but the nefarious faerie world has many more surprises. In book 2, a mysterious and menacing shape-shifter shows up at Mallory's fencing match, and before Simon and Jared can suss out, their sister disappears. .