Mike comes home with a present and says he has news for everybody, and "it has to do with water." Carol opens the box and finds airline tickets for Hawaii. Mr Philips, Mike's boss, is sending him there to check on the progress of a building Mike designed, and tickets have been provided for the whole family.
In Hawaii, David is put in charge of the Bradys and takes them on a tour of the sights before taking them to the construction site. The Bradys are having a groovy time, but there are foreshadowings of taboos and ill-luck when David tells them of the taboo that supposedly led to the Pearl Harbor disaster and that some of the old islanders are superstitious. And at the construction site it begins in earnes when a worker digs up an idol. An older worker, Mr Hanalei, warns him not to touch it as it is taboo and will bring bad luck to whoever touches it. The younger worker does not believe the superstition but uses his spade to toss it aside.
The Bradys arrive at the site. While Mike goes into the office, Greg asks David to help him check out more important sights - "like bikinis" and David suggests the surfing contest the following day, which Greg accepts. Bobby and Peter start exploring the site. Bobby finds the idol and, in the mistaken belief it brings good luck, starts wearing it as a good luck charm.
Bobby starts practicing ukelele and receives a recital from Don Ho himself. Bobby puts meeting Don Ho down to his good luck charm. Cindy does not think it is such a lucky charm when Bobby sits on the ukelele and squashes it.
The Brady boys settle down for the night. When Bobby (still wearing the idol) kids Greg, Greg throws a pillow at him. The pillow causes a wall shield hanging to fall and narrowly miss Bobby's head. Bobby thinks his good luck charm saved him.
Next morning Greg sets off for the contest while Carol, Alice the girls head for hula lessons. Alice finds the idol on the floor. Realizing it must have fallen off Bobby's neck, she looks after it by wearing it. At the hula lesson, Alice hurts herself and has to withdraw. Later, she gives the idol back to Bobby at the beach. Bobby offers it to Greg for good luck during the contest. At first Greg does well, but then he has a bad wipeout. There is no sign of him, and the family rushes into the sea to look for him.