Death on the Derelict

A squad of Imperial Marines dispatched to check out a derelict transport drifting towards an Imperial world, are ambushed after they board the transport by Alpha Legion possessed.  Caught by surprise and in close quarters the daemonic marines are able to overwhelm the boarders and launch a counter boarding operation on the small marine patrol craft.  This sudden surprise would lead to the Stragoi IV Terror raid which left nearly a quarter of the planets population dead.