Devoted to fighting chaos, (they referred to it as 'Kaos') they regarded the [[63rd expedition]] sceptically, as they thought they might be tainted by it. They were in talks with Horus and his peers when a marine tainted by the powers of Chaos infiltrated a the Hall of Devices, the Interex museum housing alien of artifacts and weapons, sabotaged the building to explode, which in many ways affirmed their initial beliefsand stole a valuable and dangerous Kinebrach sword known as an Anathame. Fights broke out between Space Marines and Interex forces until Warmaster Horus was successfully evacuated off planet.  The stolen Anathame would be the weapon that would later mortally wound [[Horus]].