A girl. A cave. A mysterious tail. What will she find?

When Captain slips away, adventure-bound, a fleeting glimpse of a mysterious tail leads her and Dad into a magical cave world filled with strange and wonderful creatures.

As curiosity pulls them deeper inside, Captain can’t stop wondering, ‘What does that mysterious tail belong to?’
Will she and Dad discover its secret, or will the cave keep its magic hidden?

This rhyming picture book is a prequel to the A Big Blue Boat stories and is written as a playful sing-along that encourages children to join in from the very first page.

Perfect for fans of children’s adventure books, rhyming picture books, read-aloud stories, and imaginative exploration, this story celebrates curiosity, family, and the joy of discovery.

Ideal for ages 3–7.
Perfect for bedtime reading, classrooms, and story time sing-alongs.