From the Baltic in his last adventure, Biggles and the team find themselves somewhere a little warmer this time.

A chance meeting with Sandy Macaster, from 266 Squadron apparently, leads the team to the Marquesas islands on the trail of pearls. There they rub shoulders with Castanelli, a fiendish trader who runs the area. Helped by some local villagers, in particular a young couple called Shell-Breaker and Full-Moon, the team decamp to a small island off Tahiti and start raking in the pearls.

Of course nothing is ever that simple. There are shark attacks, octopi, hurricanes, floods, and the unwanted attentions of Castanelli and his thugs to contend with. Capt Johns definitely has a thing about giant octopi. Twice in this book the beasts cause havoc amongst the team.