The 'goodest goodies' are mid swashbuckle with those rotten rascals the pirate dinosaurs. T Rex is about to force them off a cliff into the sea, which today is infested with... sea ferrets! But Flinn and his crew make a tricky escape by sending a sea of custard their way. All except for Pearl, who sees that Dippy is about to slide off the cliff, and saves her. Later that day the kids are surprised when Dippy boards the Acorn, and it looks like she's there to stay. She tells them that Pirate code states that she must repay Pearl's good deed by saving her. And she's going to stay until she does. Tom confirms it in his Big Book of Piratey Facts. Pearl thinks it's very nice and very polite too. What harm can it do? But they soon learn exactly what harm, when Dippy gets in everybody's way... saving Pearl when she doesn't need saving; tasting her custard to see if it's poison and saving her from 'walk the plank' practice.