“It is a spy’s job—your job—to keep secrets,” he said. “I will not begrudge you that. But you must understand: You work now for His Majesty. Whatever personal secrets you hold, you may not keep, if they threaten the king. Is that clear?”

“Yes, my lord.”

“Then I will ask you: Do you know of anything that is a danger to His Majesty?”

The Templars were no threat to Charles, I was certain. In fact, they’d told me the opposite: They’d often worked to thwart plots against the French king, Louis XIV, even if they hadn’t always succeeded. So my answer could be true.

“No, my lord.”

“You received a message. May I see it?”

Again, that abrupt change of topic threw me. I reached into my doublet to hand him the letter I’d found in my shop.

He studied it carefully, silent.

An oath was made, a promise sworn

To those who wished to bind him.

But he returned, and offered scorn

And so they come to find him.

You will know the key when you see

the truth. Remember Paris.

M O I U R H J B X A M G X B H B L L

He stared at a blank space on the wall, as if he were looking out of a window, instead of at empty plaster. He remained that way for a few minutes. Then he spoke.

“Do you know what the riddle means?”

“The first part? Um… no,” I said.

“You hesitate.”

“Well… I have an idea. My friend Tom suggested it, actually. I think it might refer to the king.”

“Why?”

I went through our discussion from yesterday. “At first, I thought it might be about me. Because the letter was left for me, and I’d just returned, like it says. But I haven’t broken any oaths”—not even now, when Walsingham had called me out for lying about Paris—“so I don’t think it fits. His Majesty also returned, when he got the throne back in 1660. And there have been two murders in the palace already. I don’t know what promise he’s supposed to have scorned, but I’m guessing it relates to those deaths.”

The spymaster remained silent, staring at the wall.

“Do you think it refers to the king, my lord?” I said.

“Yes.”

“Whom do you think is the threat?”

“I’m not going to tell you.”

That was unexpected. “All right.”

He turned back to meet my eyes. “I stay silent because of something critically important you must understand.” He spread his hands. “This—this moment here—is the most dangerous time in an investigation.”

I’d figured the most dangerous time was when the bullets started flying. “Why is that, my lord?”

“The human mind,” he said, “is exceptional at recognizing patterns. So good, in fact, that when there are no patterns, we invent them to fill the gaps. Once a man’s mind is fixed on what he believes is the truth, nothing else can be real. If he finds evidence that supports his theory, then he is correct. If he finds evidence that refutes his theory, does he rethink his beliefs? Very rarely. Instead, he dismisses the evidence, or finds some way to twist it so it will fit his view of the world. He simply refuses to see.