In the Segmentum Solar, Space Marines from the Invaders 2nd Company investigated a reported Eldar sighting on Bissan. They were attacked by Word Bearers who arrived by Strike Cruiser. In the ensuing battle, a squad of Devastator Centurions staunchly defended their battle-brothers from atop the ruins of an old exodite settlement, eventually destroying many tainted tanks, Forgefiends and Helbrutes.
The Invaders Chapter launched an all-out assault on their attackers, eventually driving the traitors from the planet. The victory was attributed to the tactical awareness of Centurion Sergeant Thynor; he downed a Word Bearers Thunderhawk before the reinforcements aboard could deploy, turning the battle. Modest, he accredited the success to the precision afforded by his Omniscope.