‘My lord,’ voxed Julio. ‘The device is a cryo-cask, half a man in height. It is leaking. No one should approach any nearer. My sensorium is registering high levels of biological contaminants in the museum emanating from the cask. My guess is all these boys are infected. Keep the mortals back until we have secured the area.’

Calgar cursed under his breath. Even sloppy little insurgencies like this one seemed to have access to biological weapons. It enraged him that any of the people of Ultramar could fall prey to the manipulations of Mortarion. He tried to blame the privations of the war, but he could blame only himself.

He turned his anger on Calleduus. ‘The building is contaminated. Do you see why I did not want you to go within? Your men would have been exposed. Fortunately, my warriors are completely protected. Can we say the same for yours?’

Calleduus stood ramrod straight, his eyes forward. ‘I restate my objections, my lord – the Ultramarines should not be involving themselves in police actions.’

Calgar turned aside. Calleduus stuck to his convictions. He was an able man, Calgar reminded himself. One mistake did not make someone a failure.

‘This terrorism is part of the war that shakes the realm,’ said Calgar. ‘The Ultramarines will be seen in every theatre, no matter how small. Next time, make sure the situation does not progress so far, and we will not have to have another conversation like this. You are dismissed, vigilator optimare.’

The vigilator optimare bowed and walked away without a word, his cheeks burning with Calgar’s rebuke.

‘Ney, relay these orders,’ commanded Calgar.

‘My lord,’ responded the Ancient.

‘Summon medicae teams and cleansing units. Decontaminate these misguided young men, and have them transferred to the Massalis penal station for assessment and re-education where possible. Every effort is to be made to preserve them. Send those that test well to the penal battalions. Those who do not recant are to be publicly mindwiped and given over to the tech-adepts for servitors.’

Calgar thought a moment. He looked up at the cliffs either side of the pass, and visualised the sparsely populated glens that nestled between the mountains thereabouts. There were not many people in the area, but there were some. All it took was one infected human to kill half a civitas. The Emperor alone knew what was in that flask.

‘Evacuate the population for ten kilometres around this point. Have them all tested. Seal off the district. Station auxilia on all the major roads and place perdition beacons around the boundaries. Second three Land Speeders from the Chapter reserve to assist Vigil Opertii forces in patrolling the area. No one is to enter this part of the mountains until it is safe.’ He looked at the Terminator squad. ‘Julio, guard these children. Once they are dealt with and you are cleansed, call in a Thunderhawk. You are needed in the fleet.’

‘My lord,’ voxed Julio.