“You’ve made quite a few mistakes in this engagement, Captain. However, your first was assuming that the Emperor’s wrath would be stayed by a mere boundary.

Background

Battlefleet Koronus, officially known as Passage Watch 27-Est, is a small fleet of Imperial Navy vessels charged with the the protection of the Koronus Expanse. At the docks of Port Wander, through the Koronus Passage, and into the Expanse beyond, the grey-hulled and crimson-prowed ships of Battlefleet Koronus defend Imperial interests and provide a bulwark for the Calixis Sector against the horrors that lurk in the depths of the Halo Stars.

This fleet detachment is nominally under Sector Command, but given a great deal of leeway in pursuing its directives — defend Port Wander and other Imperial outposts and void stations along the Halo Margins, patrol the Koronus Passage, and launch expeditions into the Koronus Expanse to eliminate potential threats to the Calixis Sector. These actions gave rise to the detachment’s unofficial name amongst Navy personnel and civilians alike — Battlefleet Koronus. This squadron, commanded by Fleet-Captain Nathaniel Horne, is on extended detached duty from the rest of Battlefleet Calixis.

Apart from the interdiction of vessels suspected of smuggling between Footfall and Port Wander, they are also charged with various Long Patrols of the Sector. These patrols avoid conflict if possible, and do not actively hunt down criminals of the Imperium. They are charged with exploring every corner of the Expanse, keeping an eye on the Rogue Traders and monitoring threats that have been developed, and these vessels often operate independently of direct naval oversight for years on end.