Thomas the Tank Engine's Hidden Surprises is a lift-the-flap board book.
Thomas is looking for hidden things on the Island as he delivers passengers to the circus.
- On the cover, The rails have spikes, in the story however, the spikes disappear.
- Harold's wheels are white not black.
- In one illustration James' cab window is a different shape.
- Annie and Clarabel are missing their names in one illustration.