Cook and Line have been looking for new ways to beat the Swashbucklers and have been taking ideas from a book all about weird sea creatures. Cook has dressed up in seaweed in order to look like a leafy sea dragon, and Line has added some googly eyeballs just like the four-eyed fish. Captain Captain doesn't believe these creatures exist, even though Cook and Line insist they are in their book - along with spiny lumpsuckers, ghost shrimps, blob fish and clown frogfish. She demands they learn about some real sea creatures. But Cook and Line are determined to prove that the creatures in their book are real.