“After a falcon. It’s a name for the corwalch.”

“Then I shall call you Merlin, too. You have courage, and it seems as if you have eyes that can see a long way. I might need your eyes, some day. But tonight you can start with simpler things. You shall tell me about your home. Well, what is it?”

“If I’m to serve you . . . Of course I will tell you anything I can . . . But—” I hesitated, and he took the words from me:

“But you must have my promise that when I invade Britain no harm will come to your mother? You have it. She shall be safe, and so shall any other man or woman you may ask me to spare for their kindness to you.”

I must have been staring. “You are—very generous.”

“If I take Britain, I can afford to be. I should perhaps have made some reservations.” He smiled. “It might be difficult if you wanted an amnesty for your uncle Camlach?”

“It won’t arise,” I said. “When you take Britain, he’ll be dead.”

A silence. His lips parted to say something, but I think he changed his mind. “I said I might use those eyes of yours some day. Now, you have my promise, so let us talk. Never mind if things don’t seem important enough to tell. Let me be the judge of that.”

So I talked to him. It did not strike me as strange then that he should talk to me as if I were his equal, nor that he should spend half the night with me asking questions which in part his spies could have answered. I believe that twice, while we talked, a slave came in silently and replenished the brazier, and once I heard the clash and command of the guard changing outside the door. Ambrosius questioned, prompted, listened, sometimes writing on a tablet in front of him, sometimes staring, chin on fist, at the table-top, but more usually watching me with that steady, shadowed stare. When I hesitated, or strayed into some irrelevancy, or faltered through sheer fatigue, he would prod me back with his questions towards some unseen goal, as a muleteer goads his mule.

“This fortress on the River Seint, where your grandfather met Vortigern. How far north of Caerleon? By which road? Tell me about the road . . . How is the fortress reached from the sea?”

And: “The tower where the High King lodged, Maximus’ Tower—Macsen’s, you call it . . . Tell me about this. How many men were housed there. What road there is to the harbour . . .”

Or: “You say the King’s party halted in a valley pass, south of the Snow Hill, and the kings went aside together. Your man Cerdic said they were looking at an old stronghold on the crag. Describe the place . . . The height of the crag? How far one should see from the top, to the north . . . the south . . . the east?”