Kate had seen her father only once. Just before the trial. The WITSEC people had arranged it-secretly. They didn’t want her to be seen attending the proceedings. Only a few weeks before, one of the key government witnesses, a bookkeeper from Argot-a forty-year-old woman with two kids-had been shot dead, right on Sixth Avenue. At rush hour. It had made all the papers and news broadcasts and stirred up a whole new round of fear. That’s why they’d gotten the dog, they joked. But of course it wasn’t funny. It was scary as shit.

And anyway, all Fergus would ever do was lick you to death if anyone ever tried anything.

“C’mon, buddy!” Kate pulled Fergus over to a bench. A street mime was performing on the path, going through his routine. Something was always going on here.

In the end, Concerga, the Colombian guy from Paz, the one everybody wanted, had fled the country before trial. The other, Trujillo, was released, because with the key witness gone, the government could not make its case. Harold Kornreich was convicted. Dad’s friend. That’s why her family has been ripped apart. Her father put in jail. Dad’s golfing buddy…he was in a federal prison now, serving twenty years.

Kate glanced at the time. It was already after eight. She had to be at the lab by nine-thirty. She had to get going. She watched the performer a minute more, breaking off a piece of a PowerBar to boost her sugar level. Fergus seemed amused as well.

“He is good, yes?”

The voice came from the bench across from them, startling Kate. A man with a trim, graying beard, in a rumpled corduroy jacket and a flat golfing hat. A newspaper sat on his lap. Kate had seen him in the park a few times before.

“I am not sure I know this breed.” He smiled and gestured toward Fergus. When he leaned forward and motioned the dog over, Fergus, who didn’t have a wary bone in his body, happily obliged.

“It’s called a Labradoodle,” Kate answered. “It’s a cross between a golden Lab and a poodle.”

The man cupped Fergus’s face. “All these new things…Something else to be hopelessly out of touch with. I thought it was merely the Internet.” He smiled.

Kate smiled, too. She thought she detected some kind of accent. Anyway, Fergus seemed to be enjoying the attention.

“I’ve seen you here from time to time,” he said. “My name is Barretto. Chaim, now that we’re old friends.”

“I’m Kate,” Kate replied. The WITSEC people had warned her to always be cautious and never reveal her last name. But this guy…She felt a little foolish keeping her distance. He was harmless. “I think you already know Fergus.”

“A pleasure to meet you, Kate.” The man bowed politely. He took Fergus’s paw. “And you, too, my friend.”

They went back to watching the mime for a moment, and then he said something to her that caught her completely off guard.

“You’re a diabetic, Miss Kate, are you not?”

Kate looked at him. She felt herself grab hold of Fergus’s leash a bit more tightly. A tingle of nerves coursed down her spine.

“Please, don’t be alarmed.” The man tried to smile. “I didn’t mean to be forward. It’s just that I’ve seen you from time to time and noticed you checking yourself after you run. Occasionally you’ll take out a piece of something sweet. I didn’t mean to frighten you. My wife, she was diabetic, that’s all.”

Kate relaxed and felt a little ashamed. It riled her that she had to react this way, so guarded toward people she didn’t know. The guy was just reaching out, that’s all. And just this once, it actually felt nice to open up to someone.

“How is she,” Kate asked, “your wife?”

“Thank you,” the man said fondly, “but she’s been gone a long time.”

“I’m sorry,” Kate said, meeting his twinkling eyes.

The street performer finished. Everyone gave him a polite round of applause. Kate stood up and checked her watch. “I’m afraid I’ve got to get going, Mr. Barretto. Maybe I’ll bump into you again.”

“I hope so.” The old man doffed his cap. Then, for the second time, he said something that made her insides clutch.

“And buenos días to you, too, Fergus.”

Kate did her best to smile, starting to back away, her heart quickening. Cavetti’s voice was never far from her thoughts: “If something ever seems suspicious, Kate, just get out of there…”

She reined in Fergus’s leash. “Come on, big guy, we’ve got to get home.”

Kate headed toward the entrance to the park, telling herself not to look back. But as she approached the Avenue C gate, she glanced around.

The man had put his glasses on and gone back to reading his newspaper.

You can’t go through life being nervous of everyone, she admonished herself. He’s older than your father, Kate!

The incident in the park stayed with Kate a couple of days. It made her feel embarrassed, even a little angry. She never mentioned it to Greg.

But two days later it was the bolt to their apartment door that started to get her scared.

She was rushing home after work with her arms full of groceries. She heard the phone ringing and Fergus barking inside. Greg was at the hospital. Kate jammed her key into the lock and twisted, balancing the groceries on her knee.

The door wouldn’t open. The dead bolt was shut.

Kate felt a flash of alarm ripple through her.

The dead bolt was never shut.

They never locked it.

It was one of those heavy steel contraptions, like they used on warehouse doors. It was always such a headache to open. And it kept getting stuck. The trial was long over. The place was alarmed. The lease and the phone were both in Greg’s name.

Kate fumbled for the dead-bolt key, warily pushing open the door.

Something wasn’t right…

Kate knew it as soon as she stepped in.

“Greg…?” she called. But she knew that Greg wasn’t there. Fergus wagged his way up to her. Kate scanned around. Everything seemed in place. The apartment had high ceilings and tall, arched windows looking east over Avenue C. The mess was still there-magazines, pillows, a water bottle, the TV remote on the couch-just as she’d left it this morning.

It was weird, and a little creepy. She knew it didn’t make sense. She petted Fergus. Everything seemed the same.

She just couldn’t put away the feeling that someone had been inside.

Then, the very next day, she and Tina were having coffee in the research unit’s cafeteria.

They’d been working together for a year now, and they had pretty much become best friends. Sisters. In fact, since Tina had dyed her hair lighter, people thought they were even starting to look a little alike.

Tina was telling Kate about this new project Packer had given her. “Injecting this isotrophic solution into the nucleic material. It basically disperses the surface fluid and…”

Suddenly Kate felt her attention drawn to something across the room.

This guy, at the far end of the cafeteria, at a table by himself. He had short, wiry hair, sideburns, a dark mustache. Hispanic features. Kate had the sensation she’d seen him somewhere before. She just couldn’t place where… Every once in a while now, she noticed his gaze through the crowd glancing toward her.

She tried to stay with Tina, but she kept glancing up at the guy, who once or twice met her eyes. It made her uneasy. But she had to admit she’d been feeling uneasy a lot lately…since that female witness was killed on Sixth Avenue.

When she looked back again, the guy was gone.

“Earth to Kate. Hello…” Tina snapped her fingers. “I know this is boring. But are you still with me?”

“Sorry,” Kate said. “Isotrophic solution…” She looked around.

Then she saw the man again.

This time he had gotten up. He was threading his way through the tables. Toward her. He had on a dark raincoat, which fell open, as if he was going for something. Kate felt a stab of alarm.