Amsterdam, The Netherlands

Once you get to Amsterdam, Sam, your life will be in danger. You can't trust anyone.

Remembering Allison Gracelyn's last warning before she'd boarded the plane in Phoenix, Samantha St. John stood waiting in the lobby of Central Station, Amsterdam's main railway station, and forced the tension and doubt away. You were warned about the danger, she chided herself. You didn't tell your lover about it, but you told your sister.

Guilt stung her, but she didn't give in to it. Riley McLane was her lover and had been a big part of her life for almost nineteen months now. But she wasn't used to sharing everything in her life. There were parts she wasn't ready to share — didn't know how to share. Being alone was natural; being part of a couple wasn't.

Riley was a CIA agent, as she was, but with a lot more fieldwork experience than she'd had. Normally she acted as support, specializing in languages and computers. Riley was definitely hands-on for retrievals and terminations.

Riley had a tendency to be overprotective and a control freak, which could be endearing, Sam had found. But for her current mission, she needed backup with no questions asked. Since she and her sister had been planning to get together for a while, Sam had elected to ask Elle to come with her.

Sam's sister was an intelligence agent as well. Elle worked for the Russian government's SVR, which was that country's equivalent of the CIA. Although they'd known each other less than a year and a half, Sam knew Elle wouldn't ask a lot of questions if Sam asked her not to. That was one of the things Sam truly appreciated about her sister.

And if things truly got dangerous on the assignment, it would be easier to disappear with Elle, who had been to Amsterdam several times before, than with Riley, who had only a passing acquaintance with the country. Sam told herself that was the real reason for her decision, but she knew she didn't want to put Riley in harm's way if she couldn't tell him why she was doing it.

And she couldn't tell him, because she didn't know. Only Allison and Alexandra Forsythe's request, and the Athena Academy bond between them, had moved her into action.

Dozens of other people waited for the train as well. Night lurked dark and mysterious outside the station windows, and the red glow of the red-light district in the distance held the promise of forbidden ecstasy. Music in several languages boomed from personal entertainment systems. Children and teenagers played video games while parents consulted travel brochures. Monitors broadcast information and news from around the world. The hustle and bustle of the station became an ocean of sight and sound that pressed against her senses.

Sam wore dark blue notch-tab capri pants and a white scoop neck sweater. She'd left her shoulder-length, white-blond hair loose, and dark sunglasses hid her ice-blue eyes even though it was dark outside. According to the tourist pamphlets, the area was rife with pickpockets and purse- snatchers. At five feet three inches tall and slender, she knew she'd be a target for predators. As a safeguard, she carried her ID, passport and cash in a pocket. She felt naked without a weapon.

And she was nervous.

You have every right to be nervous, she told herself. You're meeting your sister in person for the fourth time in your whole life.

For all of her childhood that she could remember, Sam had been an orphan raised in foster homes. She'd learned to be quiet and self-contained. She wasn't used to family. Most of the foster homes she'd been in preferred not to see their charges. She'd learned to spend incredible amounts of time surfing the Internet.

Ultimately, it had been her interest in computers that had saved her, though her salvation had taken a strange route. When she'd been nine years old, she'd hacked into a sensitive government site, not really knowing what she was getting into, just plugging away at a barrier that had stymied her young mind. Her success had triggered an armed invasion by federal forces.

But a judge's decision and government intervention had brought her to the attention of the Athena Academy for the Advancement of Women. The seventh-through-twelfth-grade school was a special academy set up for the smartest, most promising young women to learn and explore their every potential.

While there, Sam had come to know the only family she'd ever felt part of. The Cassandras. Her orientation group had all been assigned at random, but their senior student leader, Lorraine "Rainy" Miller, had united them into a group of best friends. Even graduation hadn't ended that relationship.

Rainy's recent murder and the fallout from their investigation and eventual exposure of the killers had only drawn the Cassandras closer. Sam hadn't needed anything outside that world.

Until she'd found out about Elle Petrenko.

Last year, Sam had been detained by the CIA and accused of being responsible for a double-cross in Berzhaan that had triggered a lot of adverse publicity for the United States. No one expected Sam to have an evil twin.

But Elle Petrenko was her twin, separated from Sam when they were barely toddlers when their parents, who had been Russian double agents for the British intelligence agency MI-6, were murdered. The events around those deaths and how Sam eventually was abandoned in America still hadn't been explained.

Thankfully, Elle hadn't been an evil twin. She'd merely been a Russian agent performing her own mission in Berzhaan. Neither Sam nor Elle had known the other existed, but once they'd met, each of them had felt as if a missing piece had been restored to them. Though their lives were worlds apart and filled with covert responsibilities, they made an effort to stay in touch by phone and e-mail and meet when they could.

So, for the fourth meeting, Sam thought glumly, it's all, "Come to see me in Amsterdam and try not to die." What kind of sister am I? She sighed, because she truly didn't know the answer to that question at present.

She had mixed emotions. On one hand, she wanted to see Elle and they'd already made arrangements to be together this week, which had been hard to plan to begin with. Giving up the time wasn't something Sam was willing to do. But neither was turning away from a request Allison and Alex had tendered, knowing full well Sam was planning on seeing Elle.

On the other hand, Sam knew how valuable Elle would be in Amsterdam, a place Sam had never been. Being a good agent was all about having resources in place in the field. So what are you? she asked herself. A sister, an agent or a rat?

"Hi."

Startled, Sam turned to look at the speaker. He'd come up behind her quietly.

The man was tall, at least six foot three, with broad shoulders and lean hips. His shaved head gave him a look of menace, and a reddish soul patch made a point on his lower lip. Gray-green hazel eyes, like those of a big jungle cat, surveyed her impassively and held deep melancholy. The black biker leathers and heavy-metal concert T-shirt didn't give much away. He could have been a dockworker or a Goth.

"Are youAmerican?" The man spoke English flawlessly. Because she felt contrary and because she didn't want to let anyone know her business, Sam answered in French.

"I don't speak English. Do you speak French?" Languages and computers were her specialty at the CIA.

He switched to German, which she also understood. "No French. I speak German."

Sam decided to cut the guy a break. He might even know more languages. She spoke in German. "Your German is very good."

"I'm told my English is really good, too," he said.

"I wouldn't know," Sam replied.

The man shrugged. "I'm amazed."

Sam arched an eyebrow.

"You're so gifted linguistically."

"What makes you think that?"

Again the shrug, just a slight lift of the broad, leather- covered shoulders. "You speak French. You speak German." He reached out slowly, without threat, and touched the pamphlet in her hand. "And you read English. Quite an accomplishment."

Glancing down, Sam saw that she was indeed holding an English language pamphlet. "Busted." She smiled, but she was wary at the same time. The man was very observant.

"I came over because you look like a tourist. This is a dangerous place for tourists."

"You just volunteer to wait with strangers in the train station?"

He gave a slight nod. "It's a hobby."

"Maybe," Sam said sweetly, "you should seek counseling."

Perhaps he had a comeback for that, but Sam didn't find out. At that moment the warning Klaxons went off, filling the station with noise and vibration. The crowd moved around her, getting ready for the train's arrival.

In that moment, Sam got a clue as to what the man's real interest was. Two men dressed in casual streetwear moved toward the platform. They had short, military-style haircuts and wore light jackets. An air of danger clung to both of them.

The big man, dressed in black, moved with them, shifting so that they stayed in his view.

The two men kept their distance.

Sam looked at the man in black. Are you hunting them? Or avoiding them? The situation intrigued her.

The train stopped with a grinding screech of brakes. Seconds later, the doors opened and the passengers began to debark in a press of moving bodies.

Sam stood on tiptoe to peer through the crowd.

Elle Petrenko stepped out from a middle car. She was carrying a baby and chatting amiably with a woman only a little older than her, who was carrying another toddler.

A baby? Sam was shocked. Elle hadn't said anything about a baby. But then, there was a lot Sam didn't know about her twin. Elle seemed outgoing and friendly, always willing to share her life, but Sam didn't do that because of her upbringing. Naturally she assumed others held back things they didn't want known as well. But a baby?

Three meetings in person over the last eighteen months, combined with several phone calls that were, no doubt, monitored by their respective intelligence agencies, and off-the-grid e-mails — none of it could complete a relationship that had a twenty-three-year gap.

Elle wore caramel-colored twill pants and a black, short- sleeved turtleneck that flattered her slender figure. Boots and a carry-on tote completed the ensemble. Unlike Sam, Elle wore her hair up.

After a brief conversation, Elle handed the baby to the young woman, who waved goodbye and managed to head out under a full head of steam with both kids. Sam released a breath, but a bit of wistfulness tugged at her heart. She was beginning to understand what it felt like to be a sister, but what would it be like to be an aunt? Just the sight of Elle holding that baby had started a whole kaleidoscope of possibilities tumbling through Sam's head. She'd never really thought about family before. Now she was seeing generations of it ahead of her.