Sassa stared at the tall stranger in the corner. Black hair, slightly wavy. High cheekbones and dark eyes. A chin that looked carved from granite and a perfectly trimmed goatee with a little five-o’clock shadow behind it. Maybe he’d had a rough night, too, as rough as hers. But those wide shoulders looked like they could handle anything that came his way, and he was handsome. Too handsome. She’d learned all about handsome men and their oh-so-charming ways from her ex.

      “Excuse me. Exactly who are you?” The you came out with all the scorn she had for his type and her gaze scoured down the green uniform to the gun belt wrapped around his waist.

      Green uniform. “Wait...are you Sam’s young man? The border patrol agent he was watching for?”

      “Yes, I am.”

      She was exhausted, worn to a frazzle, and now she was angry. Ready to lash out.

      “You were late...too late.”

      He winced as if in pain.

      Good. At least one of these cold, brusque men with their blank faces had the decency to feel something for Sam...kind, gentle Sam. Tears pricked her eyes and she looked down, refusing to cry again, especially in front of the man who had failed Sam in so many ways.

      “You’re the ‘official’ he contacted regarding the Black Knights. You’ve been talking to him since all this started. Why didn’t you stop that man from killing him? And why on earth did he contact the border patrol in the first place?”

      That verbal dart seemed to strike a chord. He straightened his broad shoulders. “I head up the border patrol’s bio-terrorism section in Riverside. Sam and I had a previous connection regarding a species of plant coming in from Mexico. I’m a biologist. He knew I’d understand the pathogen’s danger.”

      His words didn’t mollify Sassa. Sam was dead. No amount of credentials, connections or degrees would change that. Besides...

      “There is no formula.” She grated it out, determined to make her point.

      “Yes, there is, Sassa. You were right. The pathogen’s potential terrified Sam. He wanted to develop a cure. We provided him with the equipment to work from a secret lab in his home.”

      Sassa wanted to snipe and argue, but what he said struck deep. His words made sense and rang with truth. Sam had been distracted, preoccupied for months, like he behaved when working on a project. She’d thought he was spending more time with his wife. June deserved the attention, so Sassa never questioned the time off or the extra hours.

      A thought hit her like a blow. “He had no resources. He had to access the internet. These people could have hacked the computer in his home and discovered he was working on a formula.”

      De Luca shook his head. “He wasn’t hacked. We supplied him with a private server connected directly to ours. He had the best computer protection our government could provide. And...he wasn’t working on the formula. He completed it.”

      “The virus is real. And now they have it,” she whispered. Cold swept over her, so deep and chilling, her hands trembled.

      “How...how could you let this happen?” Her tone was harsh. The dam holding her emotions in check had burst. “Why didn’t you stop him from developing it? Why weren’t you on time?”

      Her words seemed to reach their target. De Luca winced as if she’d actually struck him.

      “Don’t be so hard on Officer De Luca, Ms. Nilsson.” She turned toward the lead agent, ready to lash out at him, too. “The Black Knights created a very complicated diversion—a bomb scare in the airport precisely at the right moment. Besides, we didn’t leave Dr. Kruger unprotected. We had a man following you both throughout the trip. We found his body in a bathroom stall on the upper floor, not far from where you exited the plane.”

      Sassa stared at Kopack. The hot flames inside her died out. A man had been following them, watching them everywhere they’d gone on the trip, and she had no clue? She should have known. Should have been more aware, more cautious. Paid more attention to Sam. Instead she’d been focused on herself, her own problems and her ambition to gain a name for herself at the conference.

      And she had the audacity to blame De Luca for his faults. The heat of shame tinged her cheeks. She’d failed Sam. The truth swamped her and threatened to drown her. A familiar sinking feeling trickled through her but she fought it. She might have failed Sam in his last days, but she wouldn’t fail him in his death. She’d make the people responsible pay. Her mind kicked into overdrive.

      “These so-called Black Knights... They seem to be everywhere. Know everything.”

      Kopack agreed and opened a file. “They are one of the most technically competent terrorist groups out there. All thanks to their leader, Nikolai Chekhov.” He pulled a photo out of the file and handed it to her. “Do you recognize him?”

      She studied the man in the photo and noted the waxy complexion. “Yes, he looks like the man who stabbed Sam. I recognize the strange appearance of his skin. But he had black hair.”

      “He was wearing a wig. We found it on the ground in the parking lot.”

      “He can’t hide that skin. It looks half dead.”

      “That’s because it is. Chekhov’s parents were brilliant nuclear physicists working at Chernobyl. His family survived the accident and immigrated to the US. In the subsequent years, Chekhov watched his parents and his older sister die from different forms of cancer, all due to radiation exposure. Chekhov didn’t escape their fate. He has severe nerve damage. It’s killing him, too, but at a much slower rate.”

      “He wants vengeance.”

      “Yes, and he’s very good at getting what he wants. Five years ago he joined the rather benign Knights and slowly but surely began to recruit brilliant sociopaths like himself. Eventually they took over the group and changed the name to the Black Knights, with a different goal. They don’t want to protect the environment but to destroy mankind’s destructive technological progress.”

      Sassa pressed a hand to her forehead. In spite of her determination, her overworked mind was beginning to spin. “But they neglected to change their web page and include that little piece of information. That’s why Sam thought they were safe.”

      “Chekhov believed he’d found another conversion with Dr. Kruger. He wasn’t happy when he found out he was wrong about the good doctor’s intentions...and Chekhov doesn’t like to be wrong. He sent his right-hand man to watch over the professor.”

      He pulled out another photo and handed it to her. “My people spotted him on security film in and around the campus.”

      Sassa stared at the agent, unable to move. At last, she looked at the picture of a stocky man with a long black beard and a ponytail. She had to work hard to get her eyes to focus. Finally, her blurred vision cleared. She closed her eyes, dropped her forehead to her hand and shook her head. “I don’t recognize him. I don’t think I’ve ever seen him. Sam developed the formula and I didn’t know... Men have been watching us on campus and following us...around the world, and I’m clueless. I’m sorry, Agent Kopack, but I’m useless to you.”

      She was no longer able to fight the familiar feeling of failure, and it moved over her in a wave that dragged her body down. Tears came again. She couldn’t stop them this time and didn’t try. She covered her eyes with one