"In ancient Greece, 9 was the number of
the Muses, patron goddesses of the arts.
They were the daughters of Mnemosyne ('memory'),
the source of imagination, which in turn is
the carrier of archetypal, elementary ideas to
artistic realization in the field of space-time."
— Joseph Campbell in The Inner Reaches of Outer Space
In memoriam:
See also Raiders of the Lost Well and…
Ground plan for a game of Noughts and Crosses