MP_MQ = MR2. Using this arcane formula, known to mathematicians as "the inversion principle," architect and modernday alchemist John Pickering manages to torque a numerical sequence into a physical body. The works that emerge are in one sense magical, set firmly within the architectural tradition of the visionary form. Yet, because of the mathematical rigor that underpins them, they are also eminently rational, engineered, potent, and, indeed, buildable. The Inversion Principle steps outside the conventions of the artist's monograph by considering, on an equal level, the meticulous process of making the work and the finished forms themselves, discussing their engineering implications and the inspirations--from Stockhausen to Sputnik--behind them.