ISBN-13: 9781539405474 / Angielski / Miękka / 2016 / 188 str.
An invisible princess, a magic ring, and more adventures than you could dream of. This is what Gerald, Kathleen and Jimmy find when they stumble upon a mysterious castle. At first it all appears to be a lark. But the children soon discover they need all their bravery and ingenuity to contend with the castle's supernatural forces