The Other Log of Phileas Fogg

About a hundred years ago, a group of mutant supermen began playing a major role in our affairs. It is no accident that Tarzan, Sherlock Holmes, Captain Nemo, and Doc Savage were (are?) contemporaries. Nor was it accidental that their biographers titillated their public with hints of their true natures while not daring to part the veil. Just what was it that restrained them from telling all?