This children's book, a follow-up to the 2012 original and written in verse, tells the story of Martin the Marlin and his friend, Steven. One day while swimming together, they come upon Daphne the Dolphin, who's helplessly tangled in a rope from a fishing net. Martin and Steven work together to set Daphne free and make a new friend in the process.

The book is appropriate for children of all ages, whether having it read to them by an adult or reading it themselves.