“I did, to the Lady Æthelflaed, and I kept that oath.”

“You did keep it,” he agreed. He was staring into the ditch where some skims of ice still lingered. “I want your oath, Lord Uhtred,” he said.

So that was why he had summoned me! No wonder he had been nervous. He turned his head to look at me, and I saw the determination in his face. He had grown up. He was no longer a boy or even a youth. He had become as stern and unbending as Alfred, his grandfather. “My oath?” I asked, because I was not sure what else to say.

“I want the same oath you gave to the Lady Æthelflaed,” he said calmly.

“I swore to serve her,” I said.

“I know.”

I owed Æthelstan. He had been beside me when we recaptured Bebbanburg, and he had fought well there even though he had had no need to be in that fight. So yes, I owed him, but did he know he was asking the impossible? We live by oaths and we can die by them. To give an oath is to harness a life to a promise, and to break an oath is to tempt the punishment of the gods. “I swore loyalty to King Sigtryggr,” I said, “and I cannot break that oath. How can I serve both you and him?”

“You can swear an oath,” he said, “that you will never oppose me, never thwart me.”

“And if you invade Northumbria?”

“Then you will not fight me.”

“And my oath to my son-in-law?” I asked. “If,” I paused, “when you invade Northumbria my oath to Sigtryggr means I must oppose you. You would want me to break that oath?”

“It is a pagan oath,” he said, “and therefore meaningless.”

“Like the oath you took from Ingilmundr?” I asked, and he had no reply to that. “My oath to Sigtryggr rules my life, lord Prince,” I spoke his title with condescension. “I swore to the Lady Æthelflaed that I would protect you, and I will. And if you fight Sigtryggr I will keep that oath by doing my best to capture you in battle and not kill you.” I shook my head. “No, lord Prince, I will not swear to serve you.”

“I am sorry,” he said.

“And now, lord Prince,” I went on, “I am riding to find Brother Osric. Unless, of course, you choose to stop me.”

He shook his head. “I will not stop you.”

I watched him walk away. I was angry that he had asked for my oath. He should have known me better, but then I told myself he was growing into his authority, that he was testing it.

And I was pursuing Arnborg. Ingilmundr had told me that his uncle, Sköll Grimmarson, had received the allegiance of Norsemen settled south of the Ribbel, and I assumed Arnborg was one of those men. And Arnborg had sheltered Brother Osric, Brother Beadwulf, who had lied to me. I wanted to know why, and I suspected that Brother Beadwulf, after leaving us at Mameceaster, would have gone back to Arnborg’s steading. So to find the monk I needed to go north.