Event · M31

Opening of the Labyrinth

The Opening of the Labyrinth denotes the episode, placed around 007.M31, in which the primarch Corvus Corax descended beneath the Imperial Palace on Terra to recover gene-stock from the Emperor’s Primarch Project. Corax arrived in the Sol system with the remnants of his force shortly after the massacre at Isstvan V; his vessel was intercepted and searched by Imperial Fists under Captain Noriz before being escorted on to Terra. On arrival, Corax found the Emperor withdrawn deep beneath the Palace, occupied with the webway project, while Malcador the Sigillite governed in his stead and Rogal Dorn oversaw the fortification of the Palace against the coming siege. Denied immediate audience with his father, Corax is recorded as having argued bitterly with both Dorn and Malcador over the refusal. Accounts differ as to what followed: one holds that the Emperor communicated with Corax psychically through Malcador as intermediary, while another describes the Emperor granting Corax a vision directly. By whichever means, Corax’s mind was left bearing implanted memories of the Primarch Project and of the location of the ancient laboratory in which its work had been conducted, a site protected by a constantly shifting subterranean maze known as the Labyrinth. Accompanied by a small detachment of Custodian Guard, a Mechanicum Magos Biologis, and his own honour guard, Corax entered the Labyrinth. Though his force suffered losses within its passages, Corax stationed his warriors at the critical points required at the critical moments, overloading the structure’s randomly shifting mechanism and jamming it open. He thereby recovered the common primarch genome and its accompanying technology, carrying it back towards Deliverance, where it would inform the subsequent Raptors programme.

See where Opening of the Labyrinth occurred on the galactic map during the Horus Heresy.

Open in universe