Calling card of a poison ship

Draxis IV- A ship emerged from the warp rift that had seen seven worlds swallowed up by.  Emergency beacons on the ship claimed them to be survivors of the warp rift and the horrors within.  As the ship got close it veered and made to transit back into the warp heading in further to Imperial space.  Before it jumped however several escape pods launched themselves onto the surface of Draxis IV.  Out emerged poxwalkers bringing the plague to the Imperial world.  The Death Guard within the rift had reverted back to a tactic from the Horus Heresy- The use of so called "poison ships" To spread plague and destruction ahead of the Death Guard Legion.