In Cannibal Adventure Hal and Roger Hunt are exploring the dangerous and largely uncharted islands of Papua New Guinea, collecting strange and rare animals. They come to understand the ways of an isolated cannibal tribe as they work together, risking their lives to capture ferocious wild creatures including man eating crocodiles and giant venomous snakes. The trip takes an unexpected turn when the boys begin to suspect that a criminal from their past is back to take revenge on the two young naturalists.
In Arctic Adventure the boys are in Greenland on another mission to collect unusual animals. With the young Inuit Olrik to guide them, Hal and Roger brave the freezing environment of the Arctic, battling wild storms, polar bears, killer whales and enormous crumbling icebergs. They explore bizarre underground cities and pass through the wondrous North Pole. However, Olrik's best efforts to protect the boys from the harsh conditions of this sub-zero world are hampered by a much scarier force than any of the natural forces at work in the icy world of Arctic - man.