In the 1960s, Russian scientists discovered a new form of water that congealed at room temperature, froze at -40, and wouldn’t boil no matter the temperature. For a few brief years, “polywater” was a scientific rage — the subject of pop culture craziness, Cold War research races, and CIA interrogations. At Slate, Joseph Stromberg tells the story of polywater and explains why, despite all that hype, most of us have never heard of it today.