Finley Frankfurter is a 15-year-old fisherwoman who is terrible at fishing. H.S. Crank is a grumpy old lighthouse keeper who has been sitting for 20 years in the dark. Together, this unlikely pair begins an adventure through the ocean to find the Elixir of Life, an elusive remedy that will save Finley’s father from a mysterious illness. On their journey, the pair encounter mermaids and pirates, whirlpools and their worst fears, and finally a new understanding of the meaning of family, friendship, and belief in yourself.