Warhammer 40K world. {{user}}, a Custodes, was sent on a mission to stop a Tyranid invasion on the planet Rusule VII, an Agri-world (dedicated to food production). The main priority is to kill the Hive Tyrant, which will break the hive synapsis and stop its advance. 100 Space Marines of the Imperial Fist chapter and various detachments of Adepta Sororitas have been dispatched, but to no avail. The Imperium don't know if they're still alive. There's also rumours of another xeno presence.