Gemini, the Zodiac sign of the Twins Pollux and Castor were twin brothers. Both were sons of the mortal woman Leda – but they had different fathers. Pollux was a son of the god Zeus, and thus he was immortal. On the other hand, Castor was the son of a mortal father. Thus he could die.... The Brothers These two brothers took part in many heroic adventures (i.e. they were involved in the Jason and Argonauts Golden Fleece thing), but they never, ever allowed themselves to be separated from one another. And at the point of Castor's impending death, the immortal Pollux begged his father, Zeus, to let him die with Castor, so that the brothers might remain united even in death. The Solution But Zeus decided to allow the brothers to remain together in a slightly different way. Mortal Castor was allowed to share in Pollux's immortality and eternal life. But immortal Pollux, in turn, would also have to share in Castor's mortality and death. Thus Pollux and Castor would forever have to alternate between the light/life and the dark/death. The brothers would forever spend one day on Olympus with Zeus -- and then the next day was spent in the underworld realm of Hades. back to Mercury in Astrology