Magic Tree House: Castle of Mystery by Mary Pope Osborne
Red Fox ISBN 9781862305243
Climb the ladder to the Magic Tree House. There's a world of adventure inside!
Jack and Annie are travelling back in time again. At first, it's all very exciting, with a castle, a banquet and knights in shining armour. But when they find themselves trapped in dark, creepy dungeons, Jack and Annie will need to come up with a clever escape plan....