"Unknown Warfare?" asked Elizabeth and Katherine as if from the same mouth. Nick had his tablet to type the term into the search screen.

Williams watched him for a few seconds and pulled the corners of his mouth down. "Good idea. Check it out."

Nick paid little attention to him and drew his eyebrows together. "Just about to," he muttered, then bristled. "So, what do I have here ... Experimental Warfare. I guess that's not it. Then apparently, there's another computer game here called that. Then another link that doesn't work or maybe is only visible on the dark web. Then there's Unknown Precept, and then there's Unseen Warfare." He shook his head. "Nothing."

"Isn't it strange when you can't even find a term on Google?" said Williams, leaning back in his chair. He looked as if he had expected just that. "On Google! Where you can find anything else. There are only two possible explanations."

Elizabeth looked at him for a long time with furrowed brows. "Maybe Unknow Warfare doesn't exist."

Williams took a deep breath. "Yes, it does exist. Then why can't you find it? Simple, you don't want anyone to know about it." He pointed to the tablet. "That's why even Google can't find anything. Because the Pentagon blocks entries about it."

Elizabeth had slid to the front edge of her chair. "Unknown Warfare is the idea of the so-called Iceman?"

"Yes. The Iceman suggested to the Pentagon that they fight psychopaths with psychopaths. As a result, special units of psychos and serial killers were formed under the name Unknown Warfare, some of whom are brought directly from psychiatric hospitals to the front lines to inflict maximum terror on enemy territory. This goes so far that some perpetrators appear to be executed on death row but are headed toward the crisis area." He paused before continuing. "The Florida Meat Grinder, for example. The Kansas killer. And the Maryland Grinder." He leaned back. "I didn't believe there was such a thing for a long time. But I saw some documentation on it some time ago. And here," he pointed to the investigative file with the pictures of the Draftsman, "here it could be the same case. Only worse."

Brooks turned to the agent. "Why didn't we think of this at the time? Didn't you know that then?"

Williams took a deep breath and shook his head. "I didn't know about the Iceman at the time. At that time, the killer hadn't disappeared for years either, so there wasn't even a question of where he was, and I probably still wouldn't have figured it out."

Elizabeth closed her eyes and rubbed the bridge of her nose. "Let's summarize," she said slowly. "This man is a serial killer who was turned into a soldier. And whenever he's in a warzone, he doesn't kill --"

"Yes, he does," Brooks added. "He kills. Not in civilized society, though, but on the front lines."

"And that's what he did during the years when he wasn't in L.A. or New York anymore and not yet in Boston?" asked Katherine, her brows raised and her eyes wide.

Williams ran his hand over his beard. "That could be the explanation. As I said, I didn't believe it myself for a long time. And at the time," he looked at Brooks and Katherine, "we didn't consider the connection between the cuts and possible military insignia. We hadn't discovered the connection to the Third Reich that Nick had come across." He glanced at Nick. "Thanks, man."

Nick grinned wryly. "I'm happy to help the FBI out after all."

Brooks looked at the two men with a deep frown. "Let's be honest. We screwed up that time. And who told us." He pointed to Elizabeth, Nick and Katherine. "The three of you. Good job, guys. That can be the missing link."

Williams nodded in agreement and looked at the three Boston investigators. "Best link we've ever had."

Nick stood up and smoothed his tie. "I'll be right back. We may already have results from the camera footage."

Katherine licked her lips after her husband left the room and poured herself a glass of water. Her throat felt as dry as the Sahara Desert. "How does it work in these units?"

Williams took a deep breath and clasped his hands. "They're supposed to do the most damage possible and spread fear and terror. Preferably in important places but where a reporter would never get to. But if a picture of massacres does leak out, they are declared to be tribal warfare or something similar. For the general public or journalists, these units don't exist. And those who do see something are disposed of, never to be seen again."

"Images of blood and terror wouldn't be very image-boosting either," Elizabeth said with furrowed brows. "And these psychos come straight from prison or death row to these units?"

Williams gave her a long look and raised his eyebrows briefly. "I don't know exactly, but many of them have been in the Army before. Then they go off the rails. And if their pathopsychological profile is such that they're highly dangerous but also highly disciplined, they end up on the front lines."

"And what if they go berserk there? Run amok? Kill their people?"

"That is followed by immediate shooting. The military police put a lot of emphasis on that. Most of the time, anyway. It happens all the time that soldiers are killed by friendly fire. By a rookie, for example, who doesn't dare to shoot others and instead accidentally fires at his people when he does shoot. Or by an Unknown Warfare psychopath, who might kill one of his men and a hundred enemies. The higher the cover contribution of such a fighter, the more own men you may kill before it has consequences. Again, that's the Pentagon's elementary contribution margin logic."

Katherine emptied the glass halfway with one swig. "These guys, are they comfortable in their unit?"

Williams pulled the corners of his mouth down and nodded. "I guess you could say that, Kate. They can let off steam all they want. Those guys make a good six figures a year, a lot more even than people in private mercenary units. And more than other mercenaries, some of whom stick their necks out for three hundred dollars a day, and then only for deployment days."

Katherine nodded slowly and emptied the glass now. "And no bad press."

"No. How could there be? After all, they're not officially part of the Army at all. While regular American soldiers are prosecuted for murder and torture, that doesn't apply to these units. One of them probably found Bin Laden's hiding place by torturing Al-Qaeda members quite violently. I once saw pictures of al-Qaeda people whose facial skin was ripped off until they spat out the information. But, of course, that's not official."

Katherine cleared her throat and looked at her sister. "Nick's sister always says there are no rules in war."

Now it was Williams who rose from his chair and shoved his hands into his pants pockets. "Supposedly, everyone takes an oath of allegiance to our Constitution, but what does that mean? Anyway, the fact is that private forces or mercenaries make it easier to start wars. It was like that in ancient Rome, where almost half the Army was mercenaries." He glanced toward the door, Nick came back in.

Nick shook his head. "So far, we've got nothing. Unfortunately, we've run the camera footage through the agencies' mainframe with no results. So if he's here somewhere, there's got to be a hold on his file."

"As long as we don't have a name," Brooks muttered, "we'll never know what unit he's in."

Elizabeth looked at Ted Williams long and hard. "If we can somehow match the perpetrator's DNA to his previous activity in the unit, maybe it will be possible to find him from there."

Williams took a long look at her and opened his mouth for a second while he thought. "In this, we have to be careful. Because the ones who might know something about it are also the ones who have little interest in anyone finding out. Even we at the FBI or the NYPD are kept from such information. The BPD is even more so. What government likes to wash dirty linen in public?"

"Who could have known anything about it?"

Again, Williams was silent for a time, as if yet another piece of forbidden information was brooding inside him. "My nephew, for one," he said, pursing his lips as Katherine sat up in surprise and looked at her sister with wide eyes.

Elizabeth rose from her chair another time. "Where's your nephew now?"

Williams gritted his teeth several times before answering, "At Langley."

Katherine now rose from her chair herself. "Langley? That's where the --"

Williams nodded. "Right. The CIA is."