Tuesday is Princess Celie's favourite day. Castle Glower magically grows a new room, a turret or sometimes an entire wing! No one quite knows how, or why, but luckily, Princess Celie has mapped out the Castle's many twists and turns.

When the king and queen disappear and Councillors from neighbouring kingdoms arrive to advise Celie, a new tower and a secret passageway appear just as Celie needs them. The Castle is definitely trying to tell her something. But it's down to Celie to find her parents, hold on to the kingdom and protect her home before it's too late.

The first page-turning adventure in a New York Times bestselling series.