“Jerry Lau was a convenient cover. He didn’t have much useful information to share himself, but he unwittingly provided us with cover to run an agent who was dynamite—a general in the technology division of China’s Ministry of State Security. His name was Zhao Mingqiu. He was in charge of over three hundred technical spies, all focused on space warfare, but over the last ten years he’d developed doubts. There was also some hostility toward the government. A cousin of his had been arrested and disappeared. And he found the work he was tasked with increasingly troubling. It took two years for us to get close to him, another year to gain his trust. But when he began to deliver, it was a gold mine. Let’s walk.”

Latham glanced over his shoulder as they set off. They walked along a barbed-wire fence beside a thin, brackish flow of oily water.

“He was code-named Counsellor. We paid him hundreds of thousands of pounds and he was worth a lot more. The only question was how to get regular intelligence off him while keeping him alive and out of the camps. We couldn’t see how to establish secure procedures while he remained in his position. Then we heard about Jerry Lau—saw he was in trouble, that he might be open to an offer: someone mobile who we could both access. Zhao thought if we could get receivers onto Lau’s ships, he’d be able to transfer data and we could collect it at our leisure. Like a dead drop. It was a brilliant idea. I approached Lau and we were in operation a couple of months later.”

Latham paused as the woods thinned and the blank walls of an industrial estate appeared on the far side of the water. When he was sure they were still alone, he continued.

“For over a year General Zhao was our most important agent in China. We had twenty specialist officers dedicated to processing the product he brought in: Chinese research, weapons systems, command structures, but also the details of their intelligence penetration of the West, what they knew about us. And that was where the problems began.

“We started seeing highly sensitive US documents coming up, ones the Chinese had acquired. These were classified beyond anything I’d encountered before—memos that weren’t even to be seen by their Congress or senior Defense Department officials. They pertained to a program code-named Ptolemy. It was huge, and entirely off the books, involving thousands of men and women, most of them employed by private contractors rather than the military, hidden in places like Quartz Hill, Palmdale.”

“Lake Ravenna.”

“Lake Ravenna, yes.” He glanced toward her. “You know about it?”

“I know it connects somehow. What are they doing there?”