In this book Gary Caton has gone back to the roots of classical astrology to refocus attention on the observational underpinnings of the astrological art. Focusing on Mercury, the swiftest and most elusive of our solar system's planets, he shows how the regular appearances and disappearances of the quicksilver planet as seen from Earth are just as important as bearers of astrological meaning as its zodiacal placements and aspects. He does this using perspectives drawn from alchemy, Qabala, and the rich mythology of Hermes/Mercury to illuminate six phases in Mercury's synodic cycle. In doing this, he shows how these phases can be used by the practicing astrologer in the delineation of horoscopes.