A quick-reading 12-year-old boy with an exceptional memory, who is in the process of mending his relationship with his parents and often feels the need to prove himself to his friends.

A 13-year-old girl with unusual physical strength and a resourceful personality, who carries a red bucket filled with tools and is the daughter of Milligan, a secret agent.

A highly intelligent 3-year-old with volatile emotions who can sometimes predict future events, often relying on her intuition to guide herself and her friends.

The kind and genius mentor of the children, known for his white hair and narcolepsy, who brings the children together to go on their journey.

Mr. Benedict’s devoted assistants and adopted daughters, both possessing remarkable abilities such as extraordinary memory and resilience.

A secret agent and the father of Kate, who is fiercely protective of the children and plays a significant role in their quest.

Old friend and farmhand of Milligan, who supports Kate with his skills and caretaking when Milligan is away.

Captain Noland, an old Navy friend of Mr. Benedict, and Cannonball, a friendly third officer, assist the children by offering them passage on their ship, the Shortcut.

The main antagonist and Mr. Benedict's twin brother, known for his narcolepsy triggered by anger, who poses a constant threat to the children.