At the height of the Webway War, renowned Mechanicum technoarchaeologist Arkhan Land ventured into that alien labyrinth in defence of the Imperium. At his side was a wounded warrior of the Blood Angels, Zephon. Now, Land faces a great challenge – to repair the damage done to Zephon, partly as a result of the tech-priest's own tinkering. But how can Land succeed where the greatest of Apothecaries have failed? And when all is done, will the only person the tech-priest comes close to calling friend still be the same man?

When the traitorous allies of Horus and Kelbor-Hal seized Mars, they sent elite hunters to apprehend key targets and ensure that any loyal resistance would fail. One such target was the legendary technoarchaeologist Arkhan Land, the discoverer of many lost treasures and curiosities from mankind's Golden Age - and the Imperial Fists cannot allow such a valuable mind to fall into the hands of the enemy. Does Land have good reason to fear his apparent saviours?