Guilliman did not believe it was free of will. There had been in Guilliman’s youth a device called the Thracian Automaton. Fashioned in the semblance of a man, the machine had played at regicide with any who would challenge it, and won every game. Questions could be put to it on matters of science and history, and the answers it gave were unerringly accurate. Konor, Guilliman’s adoptive father, had taken the boy primarch to see this marvel. Guilliman had seen through it immediately, and challenged its creator. The man had insisted that it worked from the old sciences, showing the consul and his adopted son complicated workings within the figure, but Guilliman would not be convinced, and he had leapt forwards and torn loose the mannequin. Inside the stool it sat upon was a very real, if rather short, man.

The man had proved to be a marvellous polymath, if a cheat, and he had spent many years serving Guilliman’s foster father.

The Thracian Automaton had been a powerful lesson. It was probable that the Cawl Inferior was an inverse of that device: a real machine intelligence masquerading as a pretence. Guilliman was no technologist of the ability his brothers Perturabo, Vulkan or Ferrus Manus had been, but he doubted that the archmagos was telling him the complete truth about how the machinery worked. It was clearly partly psychic in nature, a blend of various xenos and Imperial technologies, which made it heretical by the tenets of the Adeptus Mechanicus in several regards, whether it could think or not.

‘The final answer is no, as it is every time,’ said Guilliman.

The machine clicked deep in its cybernetic innards, filing the response for later broadcast to Cawl.

‘Give me Cawl’s report,’ commanded Guilliman.

‘The Conclave Acquisitorius proceeds through the galaxy. Cawl has recently finished war operations on Cadmus Phosp. Unfortunately, the pylons discovered there are too degraded to be reactivated, and so he must begin his quest anew.’

‘So he cannot yet reproduce the technology.’

‘Regrettably, not yet. Not on the scale necessary for your ends, my lord.’ The slack mouths of the heads continued their jerky aping of the machine’s voice. ‘Archmagos Cawl has formulated a number of smaller experimental devices that project a similar effect to the xenos originals, albeit to a lesser degree. He has provided several to seal the Pit of Raukos. They will arrive soon.’

‘I am aware of this. That is why we are here. That is why the battle for Raukos was fought.’

‘Forgive me, my lord, I can say only what my cogitators select as the most appropriate response according to Cawl’s code,’ said the machine. Was this a lie, or a genuine artefact of how the machine worked? Cawl obfuscated everything.

‘Will the devices work?’