"Ark Saviour, this is Ark Actual. Report."
There was a brief and pregnant pause. A massive energy surge, then the convoy's signal vanished from the auspex, and they weren't responding to hails. Even Captain Praesidio was staying ominously silent. The damned Death Guard had caught them, so close to safety. Chaplain Sirius looked at the Techpriest operating the vox, who gave a tiny shake of his helm.
There was no time to mourn, Sirius decided. Swift action would decide the day. Grief had no place on his battlefield.
"Deartur! Take a Razorback and the reserve group, depart for their last known position with all immediacy. Locate and retrieve the vaccine, recover survivors with secondary priority."
"I go, in His name," the Chapter Champion replied, immediately donning his ornate helmet and striding out of the command room. Chaplain Sirius turned back to the Techpriest.
"Ferramen, prepare the Teleportarium. I shall assemble a reaction force in case Deartur is attacked. The Fourteenth will not be far off, I think. I should like to catch them unprepared for a change."
Ferramen nodded, then waved one of his chapter serfs into position on the vox before heading out. Sirius turned to the huge Aquila that sat atop the Ark Bastion's central command banks. "We shall not fail," he told it, then followed his brothers out of the room.