There was a crack of wood behind them. A man, also in a hospital gown, staggered out of the reeds. He was covered in scratches, and his eyes were blank.

‘Three! Three! Three!’ said Bolus, jabbing a clawed hand at the other.

‘Oh, that is perfect, just simply perfect,’ said Varens. ‘Hey, hey, you! Soldier! Stop!’

The man stared blankly at the water. He walked to its edge and, after staring into it for a few seconds, fell forwards face first.

‘Damn it!’ said Varens. He was frightened. The man’s actions reminded him of the way the dead had fallen into their trenches on Espandor. He hesitated, fearing the chill might kill him, but his sense of duty got the better of self-preservation, and he floundered into the lake. By then, the man had floated out several metres. Swimming even that short distance in the freezing black water drained the strength from Varens.

‘Four! Four! Four! Four!’ shouted Bolus. ‘Five! Five! Five! Five! Five!’

Two more soldiers, one man and a woman, came out of the thicket. The man plunged into the water. The woman stopped a moment, her slack face clearing.

‘Where am I?’ she said, then fainted into the lake.

‘Emperor!’ said Varens. He dragged the unresponsive first man back to shore, and hauled the woman out onto the island. The other man fought him, and sank out of sight into the peaty depths.

‘Bolus! Bolus! Help me!’

‘One, two, three, four, five!’ cackled Bolus, touching his fingers like a child learning to count.

Swearing profusely, the cold water dripping off him, Varens knelt by the first man, rolled him onto his front and began pumping on his arms. A stream of dirty water welled from the man’s mouth. When it slowed to a trickle, Varens rolled him over onto his back and pressed his lips to the man’s, breathing for him. After three breaths he pulled back and pumped the man’s chest.

‘Six! Six! Six! Six! Six! Six!’ said Bolus.

A sixth person came out the thicket. He moaned, then collapsed and went into a seizure.

By now, Varens was terrified. This was too much like what he had seen on Espandor. But there were no walking dead here, no traitors, and none of their terrible allies; the ones the officers insisted were xenos, but that rumour suggested were something else entirely. He pumped at the first man’s chest, distracted by the latest arrival. Something tickled his hand, and when he looked back he yelled in horror, and stumbled backwards.

Sickly coloured insects were crawling from the man’s mouth and nose, pouring in wriggling masses onto the soil.

‘Bolus?’ he said, his voice quiet.

Bubbles erupted out in the mere where the other man had gone down. The water boiled, and fish and other aquatic creatures bobbed to the surface dead, already squirming with the life of carrion organisms.