The story:
The explorer Dr. Archer and his daughter June are captured by the man eating Rope People whilst on a jungle expedition, but luckily a tom-tom message alerts the Phantom, who manages to reach the distant tree-top village just before the cannibals get to work on their captives.

It transpires that the Phantom has visited the village many years ago (our Phantom's grand-father), but the fact that our Phantom has not aged since then induces the Rope People to test him by forcing him to perform the same impossible feats as his grand-father did all those years ago...