The Rick Brant Science-Adventures were already getting scarce, hard to find, when I was a kid devouring all the series mystery fiction I could. But I persisted, judging the Rick Brant books especially interesting, in no small part because of the science-based storylines. This book, "The Caves of Fear," in particular, stands out in my memory. This mystery begins with cryptography and soon there's mention of heavy water, which at the time this was written meant one thing: nuclear energy. Before the end, the team of science-minded sleuths are deep underground in a lake, racing against Chinese secret agents in what turns out to be a very clever espionage tale of nuclear proliferation, c. 1951. ( )