Zane is determined to catch the "sea monster" he saw during his shipwreck, and he employs Lewis to help him. Lewis, even though looking for a part-time job, at first rejects his offer but after talking with the mermaids agrees to work with Zane to steer him off the Mako island. Cleo does not like her birthday party prepared for her as if she was still 6 years old, and goes for a long swim, but accidentally ends up where Zane and Lewis are.