John, Susan, Titty and Roger, the crew of the Swallow, take on the job of mapping the mass of small islands round Pin Mill while living on the biggest one. But who are the mysterious savages who lurk in the islands - and is the tribal totem they find in their campsite a threat of attack. ?

John, Susan, Titty and Roger, the crew of the Swallow, take on the job of mapping the mass of small islands round Pin Mill while living on the biggest one. But who are the mysterious savages who lurk in the islands - and is the tribal totem they find in their campsite a threat of attack. ?