"-thanks." Always nice to have a heads-up. Even when it's after your partner cocoons you both in a potent and highly fatal bioweapon. He's at least aware enough of Cortana's basic sensibilities that the minute she mentions the importance of his helmet, he's switching over from ambient air to reserves.

That's about how long it takes for the vent grates to burst open, and he huffs a satisfied sound as the first wave goes down in a quivering carpet of scrabbling legs and chitin. The first one that doesn't go down brings the point of his rifle up, two quick shots to shatter it into immobility and three more just like it scrambling over the shards.

"All right, let's move!" He's on his way toward the door and ready to take up the rear, trusting in Cortana and Theta to pinpoint their directive and guide them there. He's on swarm control, and after the first half-dozen shots he's locked back the rifle and snatched a shotgun out of thin air instead, blasting a hole in the wave rolling towards them.