England, 1893, and aquarium fever is at its height. Twelve-year-old Vinnie Fyfe works in the tea-shop at Brighton aquarium, and waits for her milliner mother to return from Paris. The arrival of a giant octopus changes her life for ever. Discovering a talent for art, Vinnie begins to draw the extraordinary beast. She soon realises she can communicate with the octopus through colour and - as a gripping mystery begins to unfold - discovers what true courage really means.