"Every weapon and projectile used by the hive fleets is a living organism, grown from the reconstituted biomatter of previous invasions. The Tyranids have no form of mechanical technology and, instead, harness an advanced form of biotechnology to create organic equivalents of the tools, weaponry and ammunition used by other races.... for their armies contain a creature specialised for every conceivable facet of warfare, which can be altered and regrown to suit a battle’s needs..."

"The lictor looked like a creature unto itself. It moved as a solitary organism. It had operated on its own for years, far away from the hive fleet. But it was not apart from the hive mind. That was the mistake the prey always made. Even at this corpuscular level, it was a mistake to see the lictor as a lictor, one of millions; there were not many, there was one. The lictor was the lictor. Every iteration was a copy, better than perfect for aeons of improvement, party to the actions, mistakes and successes of every other lictor that had come before. Welded to the very genes of its being were untold millions of years of experience. And it was on Baal just as it was simultaneously on a thousand other worlds throughout the galaxy.
It put ancient lessons into action. Sight was the easiest sense to fool. The lictor moved at night, when it was harder to see. Chromatic microscales lent it near perfect chameleonic ability even in the full light of day. Deformable organ clusters embedded in its skin allowed it to change its shape somewhat, enabling it to take on the rough texture of stone, or mimic fronds of vegetation. Smell was a more primal sense, harder to deceive because of it. The lictor managed that too. It had virtually no scent. Only when it flooded the air with pheromone trails to guide its kin beasts did its emissions become noticeable. By then it was too late. Most prey could hear, so it made no sound when it moved. Special arrangements of hairs baffled the whisper of its limbs moving over one another.
More esoteric senses were equally well accounted for. Its electromagnetic profile was minimal. Its brain case was shielded by internal bone structures against energy leakage. The nerves in its body were similarly cloaked. Its hooves were shaped to make the minimum of vibration, and although it could not entirely stop the perturbation of the air made by its movements, its chitinous plates were fluted in precise molecular, fractal patterns to minimise its wake. It gave off no heat. It shed no cells unless damaged. Its psychic link with the hive mind was like spider silk, gossamer thin, strong, and almost impossible to detect.
More adaptations heaped on top of more. Unlike a natural organism, which loses certain gifts in favour of others as evolution pushes it down a particular path, the lictor’s advantages were retained, new gifts stacked atop the ­others. Its genetic structure was incredibly complex. Within every cell was billions of years’ worth of adaptation, culled from every lictor, coiled up one over the other. Anything useful to its role, no matter how inconsequential seeming, it retained forever.
Every machine and psychic ability the Imperium had geared towards detection, the lictor could evade. The hive mind had consumed far more advanced races than mankind. Infiltrating Baal was child’s play. There was no need for it to employ a fraction of its considerable talents.
At night it sprinted tirelessly across the desert, sustained by bladders of super-nutritious fluid contained within its body. The roar of the hive mind was growing stronger by the day, but the lictor was not aware of the mind. It had no sentience. Instead, the mind became aware of the lictor, much in the way a man becomes aware of his limbs only when he thinks of using them.
On it pounded through the nights as the prey creatures’ clumsily engineered warrior caste gathered around the world. As Mephiston dreamed, it loped across the Waste of Enod. As Dante drew up his plans, it crossed the Bloodwise Mounts, bounding tirelessly from crag to crag, its hooves punching sharp holes in the pristine snows of the summits. Where it could, it fed upon Baal’s sparse life to supplement its nutrient fluids, but it did not tire. It stopped to avoid detection, never for rest.
By the time Commander Dante called his Great Red Council to order, the lictor was skittering through the solidified lava fields of the Demitian Badlands. The prey was cunning. If other creatures like itself had made it to Baal, they had been found and destroyed, and it was a long time before it felt the sympathetic life pulses of other tyrannic organisms.
One was all it took, for one was all, and all was one. Wherever there was a sole representative of the species, there was the hive mind.
The final night of Leviathan’s approach drew closer. The lictor burrowed into the crest of a towering dune as Balor burst over the horizon and flooded the desert with ruby light. Its eyes peered through siftings of sand.
Red day struck off a distant fortress, the black of its carved stone stark against the desert. Metal-shell prey conveyances flew from the fortress into the great star sea, and all around it were thousands of the prey warriors.
A feeble number against the onrushing trillions. If the lictor could have, it would have felt contempt. But it did not. It could not. It saw a target like a scope sees a target. It knew without thinking, without being, what it must do. Sophisticated senses appraised the fortress for weakness.
It saw nothing it could use, not yet. It needed more information.
Burrowing deeper into the sand, the lictor settled in to wait"