Footsteps and voices from outside, and he gently eased himself up to stand pressed against the wall. The door would open towards him, and anyone standing in the doorway would not see him. Or so he hoped.
The slat rattled open, and faint dusk light shone across the sill; a long arm, corded with muscle, came through the gap and took up the wooden platter. Then the platter fell, the bowl tipping and spilling cold gruel. The voices outside grew urgent. The guard was only a foot or two away now, crouching outside the door to peer through the open slat – Castus could smell the rank fat the Pict warriors smeared on their bodies. He tensed, holding his breath, muscles burning.
A rattle as the heavy oak locking bar was lifted from the door. Then the wooden boards swung slowly open. Castus waited, gripping the knife – he had seen how the guards had to stoop as they passed beneath the low stone lintel. He drew a sharp silent breath. Then he flung all his weight against the door.
The heavy boards crashed hard against the man in the door shy;way; then Castus spun on his toes and threw the door back open. The guard was reeling, pitching over against the frame of the door. Castus grabbed him by the hair and flung him down on the floor behind him. The second guard was standing just outside. He was holding a sword, but his face was blanked by surprise. Castus saw the man’s chest rising as he drew breath to shout; he launched himself through the doorway, raising his elbows with the knife levelled. The short stiff blade rammed into the guard’s throat, stabbing through his windpipe. Castus threw his arm around the man’s waist to catch him as he fell, dragging him back into the hut and kicking the door closed behind him.
For a moment he stood breathing hard. The first warrior was still on the floor, moaning and struggling to rise onto hands and knees. Castus stepped across him, locked his elbow beneath the man’s jaw and tightened his muscles, pressing down on the spine with his free hand. The warrior struggled, kicking out; then his neck twisted and snapped and he went limp.
The knife made an ugly sucking sound as he dragged it from the second man’s throat. Blood gushed and pooled, black in the shadows. Wiping the blade, Castus wrapped it in a rag and slipped it into the waistband of his breeches. Then he took the short leather cape the first guard had been wearing, put it on and picked up the fallen sword. For a few moments he crouched, waiting for his heartbeat to slow, the energy of killing to ease. He needed to be calm now, he told himself. Calm and quick.
He cracked open the door again. It was almost fully dark, and the compound was deserted. No other warriors in sight, none drawn by the brief bloody struggle at the hut door. Castus concealed the sword beneath his cape, and then opened the door wide enough to slip outside. The air tasted like cold clean water, or the most refreshing wine.
There were animal pens to either side of the hut, and behind it a short slope down to the wall and the palisade that ringed the upper compound of the fort. Castus edged along the wall; then he crouched beside the wattle fence of the animal pen. He drew up the hood of the cloak, hoping that in the darkness he might resemble a Pict to any distant watcher. But there was blood all down his right arm and splashed over the chest of his tunic. He had not noticed it before. He scanned the line of the wall, and saw a single sentry standing on the parapet behind the wooden palisade, about a bowshot distant. The wall on this side was only shoulder height, but Castus knew that it fell away much further on the far side, as the slope of the hill descended.
Turning, he stared back across the compound; there, on the far side, not fifty paces away, was the hut of Julius Decentius. How much time, he thought, before the other warriors noticed that the guards were missing? How much time before they went to investigate? Quickly, before caution gripped him again, he shoved himself away from the wall and began running, head down, across the compound.
As he neared the hut he heard a burst of laughter, and saw a spill of firelight from an opening door. He threw himself down beside a pen on the far side of the compound, but it was only a woman coming from one of the other huts with a bowl of cooking scraps. She flung them into the pen, and Castus heard the grunt and shove of pigs. He waited until the woman had returned inside, then scrambled up and ran to the door of Decentius’s hut.
He did not know how many people might be inside. Decentius may have warriors with him. He may even have a wife and chil shy;dren – Castus had not considered that. But he could not turn back now. A glow came from inside, showing between the boards of the door. He rapped on the boards with his fist, and heard a voice from within.
As soon as the latch was raised he threw himself against the door. The figure on the far side reeled back, saying something in Pictish; then Castus punched him hard on the jaw and he fell. Closing the door behind him, Castus drew the sword from beneath his cloak. Decentius was sprawled on the ground beside the hearth, an upended stool beside him. There was nobody else in the hut, and Castus stepped away from the door with the sword held low.
‘Centurion,’ the man said, holding his jaw, ‘what are you-?’
‘I’ve got a message for Aelius Marcellinus,’ Castus said in a low whisper. He was standing close to the fallen man, close enough to strike. Decentius managed to sit up. His eyes flicked across the room to the Roman cavalry sword on the far side of the hearth.
‘Aelius Marcellinus is dead.’
‘That’s right. And you can give him the message when you meet him in the land of Hades. Tell him: Aurelius Castus sent me to follow you.’
He drew back his arm to strike, but the man raised a hand, imploring.
‘Wait!’ he said. ‘Please… you’re mistaken!’
‘Mistaken how?’ Do it now, Castus told himself. Strike, and get it done. But then he remembered the renegade’s words at the parley before the besieged fort. The empire has betrayed you… Don’t die for emperors who despise you!
‘I…’ Decentius said, kneeling now. ‘I am a loyal servant of Rome.’
‘You’re a renegade and a traitor. Now you’ll die.’
‘I’m not a traitor, no! I’ve been an exile for ten years, that’s true. But my loyalties have always been to the emperors.’ He was speaking quickly. His eyes still flickered towards the sword. ‘I have… I’ve been in communication, these last two years, with agents of the imperial government, a very highly placed officer of the Notaries, from Treveris…’
Castus felt his brow cool suddenly. His arm ached from holding the sword. He remembered the strange subtle man in the praetorium at Eboracum, months before. His questions about the loyalties of the army. Nigrinus.
‘He came here?’
‘No. No, we communicated by messenger. I have documents, coded documents – if you’ll allow me to show you…’
‘I’ve got no use for documents. Explain quickly.’
‘I was promised,’ the man said. ‘Promised a full pardon, the restoration of my military rank and honour, my ancestral lands… I would have done anything for that, centurion. All these years exiled in this place, living in a hovel surrounded by savages. What would I not have done?’
‘What did you do?’ Castus growled. He stepped closer and seized the man by the shoulder. Decentius hung limply from his fist.
‘I was ordered… to provoke the tribes into an uprising against Rome. To arrange the deaths of the king and his supporters.’