'There is no limit,' he said. 'None that I can see, except the long-suffering of God. You know the man as Ivery, and you knew him as that other whom you believed to have been shot one summer morning and decently buried. You feared the second - at least if you didn't, I did - most mortally. You realized that we feared Ivery, and you knew enough about him to see his fiendish cleverness.
Well, you have the two men combined in one man. Ivery was the best brain Macgillivray and I ever encountered, the most cunning and patient and long-sighted. Combine him with the other, the chameleon who can blend himself with his environment, and has as many personalities as there are types and traits on the earth.
What kind of enemy is that to have to fight?'
'I admit it's a steep proposition. But after all how much ill can he do? There are pretty strict limits to the activity of even the cleverest spy.'
'I agree. But this man is not a spy who buys a few wretched subordinates and steals a dozen private letters. He's a genius who has been living as part of our English life. There's nothing he hasn't seen. He's been on terms of intimacy with all kinds of politicians. We know that. He did it as Ivery. They rather liked him, for he was clever and flattered them, and they told him things.
But God knows what he saw and heard in his other personalities.
For all I know he may have breakfasted at Downing Street with letters of introduction from President Wilson, or visited the Grand Fleet as a distinguished neutral. Then think of the women; how they talk. We're the leakiest society on earth, and we safeguard ourselves by keeping dangerous people out of it. We trust to our outer barrage. But anyone who has really slipped inside has a million chances. And this, remember, is one man in ten millions, a man whose brain never sleeps for a moment, who is quick to seize the slightest hint, who can piece a plan together out of a dozen bits of gossip. It's like - it's as if the Chief of the Intelligence Department were suddenly to desert to the enemy ... The ordinary spy knows only bits of unconnected facts. This man knows our life and our way of thinking and everything about us.'
'Well, but a treatise on English life in time of war won't do much good to the Boche.'
Sir Walter shook his head. 'Don't you realize the explosive stuff that is lying about? Ivery knows enough to make the next German peace offensive really deadly - not the blundering thing which it has been up to now, but something which gets our weak spots on the raw. He knows enough to wreck our campaign in the field.
And the awful thing is that we don't know just what he knows or what he is aiming for. This war's a packet of surprises. Both sides are struggling for the margin, the little fraction of advantage, and between evenly matched enemies it's just the extra atom of foreknowledge that tells.'
'Then we've got to push off and get after him,' I said cheerfully.
'But what are you going to do?' asked Macgillivray. 'If it were merely a question of destroying an organization it might be managed, for an organization presents a big front. But it's a question of destroying this one man, and his front is a razor edge. How are you going to find him? It's like looking for a needle in a haystack, and such a needle! A needle which can become a piece of straw or a tin-tack when it chooses!'
'All the same we've got to do it,' I said, remembering old Peter's lesson on fortitude, though I can't say I was feeling very stout-hearted.
Sir Walter flung himself wearily into an arm-chair. 'I wish Icould be an optimist,' he said, 'but it looks as if we must own defeat. I've been at this work for twenty years, and, though I've been often beaten, I've always held certain cards in the game. Now I'm hanged if I've any. It looks like a knock-out, Hannay. It's no good deluding ourselves. We're men enough to look facts in the face and tell ourselves the truth. I don't see any ray of light in the business. We've missed our shot by a hairsbreadth and that's the same as missing by miles.'
I remember he looked at Mary as if for confirmation, but she did not smile or nod. Her face was very grave and her eyes looked steadily at him. Then they moved and met mine, and they seemed to give me my marching orders.
'Sir Walter,' I said, 'three years ago you and I sat in this very room. We thought we were done to the world, as we think now.
We had just that one miserable little clue to hang on to - a dozen words scribbled in a notebook by a dead man. You thought I was mad when I asked for Scudder's book, but we put our backs into the job and in twenty-four hours we had won out. Remember that then we were fighting against time. Now we have a reasonable amount of leisure. Then we had nothing but a sentence of gibberish.
Now we have a great body of knowledge, for Blenkiron has been brooding over Ivery like an old hen, and he knows his ways of working and his breed of confederate. You've got something to work on now. Do you mean to tell me that, when the stakes are so big, you're going to chuck in your hand?'
Macgillivray raised his head. 'We know a good deal about Ivery, but Ivery's dead. We know nothing of the man who was gloriously resurrected this evening in Normandy.'
'Oh, yes we do. There are many faces to the man, but only one mind, and you know plenty about that mind.'
'I wonder,' said Sir Walter. 'How can you know a mind which has no characteristics except that it is wholly and supremely competent?
Mere mental powers won't give us a clue. We want to know the character which is behind all the personalities. Above all we want to know its foibles. If we had only a hint of some weakness we might make a plan.'
'Well, let's set down all we know,' I cried, for the more I argued the keener I grew. I told them in some detail the story of the night in the Coolin and what I had heard there.