So, Lord-Captain Claudia Black finally had the three pieces of the starmap she had sought so long - the Pearl was finally within her grasp!
Her "dreams" had been getting more and more vivid, and more and more frequently, she had been catching glimpses of her "other self" in reflective surfaces and by somewhat controlling the actions of the figure. She was almost certainly an Eldar - the armour she wore, the weapons she carried, and the long, almost asexual and totally alien reflection she saw confirmed it to her mind. The land she strode through also became clearer - the diamond-coated beaches of pure, white sand, the sweltering jungle environs, and that huge mountain, a sense of foreboding and yet hope when she saw it...
She had been taking enough carefully-balanced stimulants to keep her awake for almost a week at a time. Once she hit the "critical" level of sleep deprivation, she would take a few nights sleep using an obscura-derivative, for a deep, dreamless coma-like sleep. The crew had began to worry about her behaviour, and she continued to confide her worries with Allesaunder.
When the Medicae declared her fit to return to full duties, she began attempting to piece the starmap together. While the pieces seemed to fit together perfectly, they did nothing. They ended up resembling a large, two-tone coin - an outer ring, with the smaller disc nestled inside. Allesaunder detected residual amounts of psychic energy in the stones - moreso than when they were seperate.
Claudia called upon the skills of Blind Mag, her Chief Astropath, who in turn brought the full force of the ships' Astropathic Choir to try and activate the device. It took a lot of effort, but, finally, the wispy, delicate runes scratched into the surface of the strange, bone-like tablet began to glow, and the disc began to levitate, the two components spinning at different speeds and directions, like some twisted mockery of a gyroscope.
Allesaunder tried to read the energies given off by the tablet, but could not - he required the Lord-Captain's knowledge, implanted by the Witches, to fully access the information.
Again, she plunged herself into the Warp with Allesaunder, felt the force of raw emotion all around her, the laughter of thirsting Gods pulling at her mind, only banished by the tiny, twinkling light of the Astronomicon - The God-Emperor himself, watching over her.
Deep within the depths, like a submerged diamond, she caught sight of her prize - The Pearl! The Eldar's map guided her feet, letting her flow through the waters like she was water herself, until she could see the diamond beaches, the beautiful plantlife...
And the mountain. Burning red fire leaked from every inch of it, a hateful pyre against the darkness. She felt the rage of eons pressing in on her mind, pushing her until she could feel her soul about to crumble...
And she was out. She hit the floor, hard, and began vomiting. The experience had taken a lot out of her, but, before she was taken again to the Medicae, Allesaunder showed her the massive holo-projector of their star charts, with a new addition - floating in one area of peace amidst a roiling Warp storm.
They had a new heading - the Pearl.