The crystal egg is a surveillance device used by invading aliens known to molluscs to observe their target planets, serving both to transmit and receive images.
One was found by an antique dealer in Seven Dials, a West End district of London.
When they invaded the Mollusc occupation post, Martian coalition leaders John Carter and Gulliver Jones found one of these devices, which immediately betrayed the Aliens' intentions to invade Earth.
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The Crystal Egg are alien objects found in the homonymous tale by H.G Wells. Its association with the Molluscs is a nod to the popular theory that the aliens featured in this story are the same versions shown in the novel War of the Worlds