“It sounds like Brother Beadwulf,” Æthelstan admitted unhappily.

“And I’m going to find him,” I said.

“If it is Brother Beadwulf,” Æthelstan said, recovering his poise, “then perhaps he just wanted to help? Wanted the siege lifted?”

“So he lies to me about his name? Lies about where he’s from?”

Æthelstan frowned. “If Brother Beadwulf has transgressed then he must suffer Mercian justice.”

“Transgressed!” I mocked the word.

“He is a Mercian,” Æthelstan insisted, “and while he is on Mercian soil I forbid you to harm him. He may be in error, but he is a man of God, and therefore under my protection.”

“Then protect him,” I said savagely, “from me.”

Æthelstan bridled at that, but held his temper. “You may deliver him to me for judgment,” he said.

“I am capable, lord Prince,” I said, still savage, “of dispensing my own justice.”

“Not,” he said sharply, “inside Mercia! Here you are under my father’s authority.” He hesitated, then added, “and mine.”

“My authority,” I snarled, “is this!” I slapped Serpent-Breath’s hilt. “And on that authority, lord Prince, I am riding to find Jarl Arnborg.”

“And Brother Beadwulf?”

“Of course.”

He stood straighter, confronting me. “And if you kill another man of God,” he said, “you become my enemy.”

For a moment I had no idea what to say, and for the same moment I was tempted to tell him to stop being a pompous little earsling. I had known him and protected him since he was a child, he had been like a son to me, but in the last few years the priests had got to him. Yet the boy I had nurtured was still there, I thought, and so I suppressed my anger. “You forget,” I said, “that I swore an oath to the Lady Æthelflaed to protect you, and I will keep that oath.”

“What else did you swear to her?” he asked.

“To serve her, and I did.”

“You did,” he agreed. “You served her well, and she loved you.” He turned away, staring at the bare low branches of bog myrtle that grew in a damp patch beside a ditch. “You remember how the Lady Æthelflaed liked bog myrtle? She believed the leaves kept fleas away.” He smiled at the memory. “And you remember this ditch, lord?”

“I remember it. You killed Eardwulf here.”

“I did. I was just a boy. I had bad dreams for weeks afterward. So much blood! To this day when I smell bog myrtle I think of blood in a ditch. Why did you make me kill him?”

“Because a king must learn the cost of life and death.”

“And you want me to be king after my father?”

“No, lord Prince,” I said, surprising him. “I want Ælfweard to be king because he’s a useless piece of weasel shit, and if he invades Northumbria I’ll gut him. But if you ask me who ought to be king? You, of course.”

“And you once took an oath to protect me,” he said quietly.