The Enchanted Island

Mantissa, the black cat, sets off to rescue his brother from the Enchanted Island, but it's not clear if he's held captive or wants to be rescued. He'd gone there in search of the treasure supposedly hidden on the island. His letters explained nothing but did invite the family to join him. Mantissa, his wife and daughter, and his two nephews decide to make the dangerous journey to find out what happened. They got rather more than they bargained for, being captured by bandits, but eventually reached the Enchanted Island, more amazing than any of them had imagined. Nor was the treasure what they expected as you will see.