A world far beneath the sea, but irritatingly like our own, comprises the setting of this unlikely science fiction tale. Cadet Eden, a member of the Sub-Sea Academy, is proud to be the nephew of the man who made possible the gigantic metropolis, full fathoms five, by his invention of a substance called Edenite. But when earthquakes threaten the happy pattern of buying and selling, Cadet Eden fears that his uncle is manufacturing these catastrophes in order to shake the under-water stock market so that he can buy low. The good old man is, in the end, redeemed, when it is shown that in producing little -earthquakes he has provided an antidote against really destructive eruptions, and Cadet Eden floats proudly back to his watery enterprises. There is something fishy about this tasteless world, which despite the authors' attempt to endow it with a new dimension of reality, is, in fact, nothing more than a gross reflection of what is already a cliche of mediocre fiction.