Photep - Sanctum of Magnus: One of the primary chambers aboard the Photep was the Sanctum of Magnus. This pavilion was a grand, three-cornered pyramid of polarised glass and gold that shimmered like a half-buried diamond. Opaque from the outside, transparent on the inside, it was the perfect embodiment of the leader of the Thousand Sons. When the Thousand Sons made planetfall on a new world, the Sanctum would be disassembled and then reassembled on the planet's surface.The air within the Photep's sanctum was cool, a precisely modulated climate that owed nothing to machine control. The floor was a spiral of black and white crystal, each piece hand picked from the Reflecting Caves beneath the city of Tizca on the Thousand Sons' homeworld of Prospero and shaped by Magnus' own hand.Three Terminators of the Thousand Sons' elite Scarab Occult always stood guard at each corner. Each carried a bladed sekhem staff, and their Storm Bolters were held tightly across the jade and amber scarab design on their breastplates.Brother Amsu, the XV Legion's Standard Bearer, always stood at the entrance to the pavilion, holding a rippling banner of scarlet and ivory. He would greet and verify the identity of the Rehati, the inner coven of advisors and trusted confidants of Magnus the Red.The Rehati were drawn from the ranks of the elite Captains of the Thousand Sons' Fellowships to address whatever issues currently concerned the XV Legion. Before allowing one of the Rehati to enter the pavilion, Brother Amsu would use his innate psychic abilities to read their aetheric auras, confirming their identity more completely than any gene-scanner or molecular-reader ever could.The inside of the pavilion was surprisingly austere. Given the Imperial suspicion over the use of psychic abilities that had surrounded the Thousand Sons since their earliest days, those few mortals lucky enough to be granted an audience with Magnus the Red always expected his chambers to be hung with esoteric symbols, arcane apparatus and paraphernalia of the occult.Instead, the walls were rippling glass, the floor pale marble quarried from the ventral mountains of Prospero. Carefully positioned black tiles veined with gold formed a repeating geometric spiral that coiled out from the centre.The Captains of the Legion's Fellowships stood upon the spiral, their distance from the centre but one indication of their standing within the Rehati. Beneath the crystal apex of the pyramid a golden disc in the shape of a radiating sun met the terminations of both black and white tiles, where the Chief Librarian of the Thousand Sons stood at the heart of the gathering.Magnus the Red stood upon the golden sun. A Thousand Sons warrior's standing in the Legion was not simply measured by his proximity to the centre of the spiral, but by myriad other indicators: the position of the warrior next to him, behind him and across from him.Who was obscured, who was visible, the arc of distance between his position and the sun disc, all played their part in the dance of supremacy within the Rehati and the Legion's hierarchy. Each member’s position interacted subtly with the other, creating a web of hierarchy that only Magnus could fathom.When the Rehati met within the pavilion, the Primarch employed a unique psychic ability known as the Symbol of Thothmes that would prevent any outsiders from spying on their private conclave. The Primarch would take a golden khopesh from his belt and activate a switch, the haft extending with a smooth hiss, transforming the sickle-sword into a long-bladed polearm.Magnus then rapped the staff on the sun disc, tracing an intricate, twisting shape on the ground. The world around the gathered coven would go dim and the interior of the pyramid would be shielded from outside eyes.For the Thousand Sons, being cut off from the Immaterium was unpleasant, but no one could eavesdrop within the pyramid by any means, be they technological or psychic as long as the Symbol of Thotmes was active. Magnus had once boasted that not even the Emperor Himself could penetrate the invisible veil cast around the Rehati by the Symbol of Thothmes.