Don't is not an injunction: anything goes in this twister. Ostensibly the Penelope is following the old clipper route to the Orient, but Peter Mallard learns, past the point of no return, that he was recruited by skipper Alec Mann to search for pirate treasure on remote, rocky South Trinidad (Peter's a climber) off the coast of Brazil, and both discover that debonair Jocelyn Adrian, a problem drinker, has solved his problem by filling the emergency tank with manzanilla. Jocelyn is ticketed for home, and, almost simultaneously, Jessica Harding stows away, a decided improvement especially since she may be Peter's ""not impossible She."" She isn't, nor does the treasure enrich anyone, least of all undercutting Hernandez de Pinada, an Onassis type alerted by Jocelyn, who seems to have all of the advantages. There's a lesson drawn via some reflective rock-climbing but the real attraction is the tricky way things happen. It might have been an adult book but there's no reason it can't be for kids.