The unsinkable Walker Bean and the knights of the waxing moon

"After their perilous encounter with the sea-witches, Walker and the crew of the Jacklight find refuge on a deserted island. But it might not be as deserted as it seems--shadowy creatures have been spotted in the jungle, and strange animal tracks appear overnight. When Walker, Shiv, and Genoa discover a secret passage and mysterious ruins, the dark history of the archipelago begins to unravel"--Provided by publisher.