In 2104, lithological excavations at the Fourth Mars Colony unearthed
an artifact of unknown, seemingly non-human origin; an icosahedron of
an unrecognized, non terrestrial metallic composition, inscribed with
strange, indecipherable sigils and glyphs.

After long months of intense study, epigraphy experts on Earth ascertained
a tenuous parallel between the unknown language on the icosaherdon and
certain obscure Aztec hieroglyphics, and thus were able to extrapolate
a meaning from the unearthly inscriptions.

The translation spoke of a legendary repository of ultimate knowledge
known as the Empyreal Lexicon... a codex of alien origin said to contain
incredible cosmic secrets; arcane words and psionic waves of power which
were the keys to unlocking a network of cerebral-transferrence portals
linking the myriad galaxies of the multiverse, and also the means to
transcend the boundaries of the space-time continuum, enabling corporeal
beings to travel between dimensions and traverse at will the unknown
realms which lay between universes, tapping into the limitless energies
which permeated the sidereal fabric of the cosmos.

The translation of the Mars icosaherdon also hinted disturbingly at a
great pangalactic conflict which was waged over the possession of the
codex between the mysterious cosmic beings who had appointed themselves
the keepers of the Lexicon and some terrifying shadowy foe mentioned
only fleetingly in the alien text.

The final battle in this cataclysmic power struggle was apparently fought
in Earth's own solar system, and the Keepers of the Lexicon, their power
depleted and teetering on the verge of defeat, shattered the codex into
a myriad shards, scattering the fragments across the star system in order
to prevent the secrets of the Lexicon from falling into the hands of their
darksome nemesis.

According to the Martian artifact, several fragments of the Lexicon
were hidden on the third planet from the sun, the Earth itself.

One fragment was secreted in ancient Atlantis, another in Lemuria.
Further pieces of the cosmic codex fell to earth in Ys and eon-veiled Mu.

Still further fragments of the Lexicon were said to have been hidden
somewhere beneath the frozen surface of the bleak moon Callisto, and
on the other mysterious orbs Hyperion and Titan.

Lastly, the alien artifact spoke mysteriously of something hidden
beneath the cratered surface of Earth's own Moon.

Ascertaining co-ordinates from the Mars icosahedron, an expedition
embarked immediately from the Epsilon IV Moon Base and began
to excavate the lunar sphere.

Thus was a veiled warning unheeded, and no one could know what
to expect as the machinations of humankind breached the ancient
surface of the moon's Mare Imbrium...