A Gelfling guard named Rian found himself in skekTek’s laboratory, and discovered a vial of glowing blue liquid. The sight of it chilled his soul. Through his investigations, Rian discovered that the great Crystal was cracked, and that the Skeksis had not only cracked the Crystal, but made it dark. He learned that the Skeksis were bending the power of the Dark Crystal to serve their wicked aims. The vial of blue liquid he found was life essence. The evil Skeksis had trained beams on innocent Gelfling; the sinister beams turned the poor Gelfling into mindless walking dead, their glowing life essence drained away and stored in vials for the Skeksis to drink to slow aging.