A Tesseract Labyrinth is an arcane Necron artefact that takes the shape of a small and innocent-looking cube about the size of a closed fist. However, a Tesseract Labyrinth is nothing less than the physical manifestation of a pocket-dimensional prison gateway, utilising the Necrons' mastery over hyper-geometry and phase technology to trap enemies within its fold; from which there is no escape. Necrons have used Tesseract Labyrinths to trap and imprison C’tan Shards in the past, and Necron royalty like Necron Overlords, Necron Lords and Necron Destroyer Lords sometimes carry a Tesseract Labyrinth into battle so as to imprison a particularly troublesome enemy, or, should the tidings of war be dire enough to warrant it, release an imprisoned C'tan Shard upon their foe. Such action is not undertaken lightly by Necron rulers, for the chance of the C'tan Shard escaping re-capture after the battle is, while remote, a possibility too dangerous to be allowed.
Grey Knights Tesseract Labyrinths
Within the Sanctum Sanctorum of the Grey Knights Fortress-Monastery lies a stasis vault, and within the vault lies scores upon scores of Tesseract Labyrinths given by the mysterious creator race of the labyrinths who contacted them many millenia ago to give over the technology. Over the millennia, the Grey Knights have succeded in sealing a few dozen daemons within the chambers of Tesseract Labyrinths but these have almost exclusively been lesser creatures -- the technique has been proven only once on one of the more powerful Greater Daemons -- though the hope remains that the Tesseract Labyrinth might yet serve as a lasting means of victory against the daemonic. To capture a daemon in this fashion is not easy, for the Grey Knight must not merely defeat the daemon, but also prevent it from abandoning its mortal form before it can be captured. For a daemon to be trapped in such an extradimensional prison is literally a fate worse than death. At least when slain, the daemon's essence returns to the Warp and there petitions its dark master amongst the Ruinous Powers to grant it a new body. It is unlikely that the Grey Knights will ever have more than the number of Tesseract Labyrinths the Chapter posseses at the present, for the Imperium's relations with their creators have come to the point of hostility and the technology to create them is far beyond the skills of the Grey Knights' Techmarines. As such, the remaining Tesseract Labyrinths are used only when the Imperium's need is great.
- Black Crusade: The Tome of Fate (RPG), pg. 122
- Codex: Necrons (5th Edition), pp. 40, 82, 89-90
- Codex: Grey Knights (5th Edition), pp. 11