Stepping carefully, she inched along to where a narrow trail led up from the river. Thick willows lined the riverbank and hid everything above them. Deer tracks in the mud told her this was a place where animals came for an evening drink.

Shielding her face with her hand, she squinted upriver. If she worked fast, she could cover another mile, maybe two, before dark, gathering water samples along this stretch of river. She’d still have time to get back to her truck, winch the Zodiac onto its trailer and drive the samples back to the lab.

Nothing she’d discovered in the past two weeks added up. Someone had dumped a massive amount of fertilizer near the mouth of the river where it met the San Francisco Bay. The fertilizer had caused the worst diatom bloom ever recorded in the North Bay, and the bloom was killing harbor seals in the area. But fertilizer was expensive. Dumping that much fertilizer made no sense.

It was more than a puzzle to solve.

They’d rescued twenty seals in just the past week and however the stuff was getting into the water, she was determined to stop whoever was responsible. Seals and whales, all the marine animals, had enough problems without adding dumped chemicals into the mix.

She shrugged her backpack off her shoulders and pulled out her GPS and map. The map showed two vineyards just above where she’d landed, the first of several north of where the Susul River met the San Francisco Bay. She pulled her notebook and a sample jar from the backpack. Water lapped at her feet as she squatted to scoop some of the muddy soil into the jar. She snapped on the lid and wrote the coordinates on the front label.

She stuffed the sample jar and map into her knapsack and tossed it over the side of the Zodiac. With a flick of her hand, she freed the line from the willow branch and turned to push the boat from the tiny beach. It didn’t budge.

Bracing herself in the mud, she put her shoulder against the pontoon and shoved hard. It didn’t move even a fraction of an inch.

Great.

She was two miles from where she’d parked her truck downriver and didn’t relish the idea of trying to find a vineyard hand to help her. There’d be questions. Questions she wasn’t prepared to answer, not yet.

She walked to the bow of the Zodiac. It jutted up, maybe just enough for her to hang her weight from the front and pop up the midsection. She stepped into the river and sucked in her breath as she sank neck deep into an eddy pool. Feeling with her feet, she found a flat rock that gave her solid footing. She reached up and wrapped the bowline around her hands and tugged her full weight against it. Her hands slipped and she splashed back into the chilly water.

“It’s a bit early in the season for a swim.”

Adrenaline shot through her as she scrambled to her feet. A tall and ridiculously handsome man stood blocking the trail. He looked like he’d been airlifted out of a men’s fashion magazine. He squatted, bringing him to her eye level. She froze, unprepared for the intensity of his gaze. He had deep blue eyes, the color of the sea before a storm. Those eyes crinkled as a slow, easy smile curved his lips.

“Just testing the water,” she said with a bravado she didn’t feel.

Goose bumps rose along her arms as she sloshed out of the water and stepped onto the riverbank. She wished they were just from the cold. To give her hands something to do, she brushed ineffectively at the mud on her jeans.

“Can I give you a hand?”

He held a half-eaten sandwich, one of those piled-high deli sandwiches that Americans loved. Her stomach grumbled; she’d forgotten her own lunch. But this was no time to be thinking about food.

He didn’t look dangerous. But the expensive-looking slacks and perfectly tailored shirt he wore were out of place. She was from England—she knew a custom-tailored shirt from a Savile row tailor when she saw one. Why anyone would be wearing a three-hundred-dollar shirt and Prada loafers in river brambles was anybody’s guess.

“No,” she said, backing up a step. “I was just leaving.”

His assessing gaze sent a shiver down her spine, pushed it deep. She tugged at her shirt. Wet and plastered against her skin, it was almost transparent. She didn’t have to look down to know he could see her nipples puckered from the chilled water. She wished she’d taken the time to put on a bra.

She glanced up, and he quickly averted his eyes. Every cell in her body suddenly said flee.

She leaned over the pontoon and grabbed her backpack, rummaged to the bottom, found her jacket and pulled it on. She felt his eyes on her once again as she tugged up the zipper. At least she didn’t feel naked anymore.

She put a hand on the Zodiac, wishing that her touch would magically free it.

“What brings you up here? I don’t see many people boating in this stretch of river—just the occasional kayaker doing some bird watching. It’s mighty shallow.”

He gave her the perfect answer.

“I was looking for nesting clapper rails.”

“That shouldn’t take long,” he said. “There’ve only been a few sightings in this area since I’ve lived here. They’re endangered, you know.”

The man knew something about birds. And he was local. Could be good. Could be bad.

“I know.”

He quirked his brow. “And you’d be more likely to find clapper rails in the fields, wouldn’t you?”

He thought she was a clueless bird watcher. She should’ve chosen a different bird, but she really didn’t know the birds of the region all that well, except for the marine birds.

The man smiled again.

A smile shouldn’t send a zip of unnerving energy straight into her, but it did. She’d sunk herself in her work for so long, studiously avoiding exactly that kind of smile. He had the ease of a man who knew the effect he had on women. An ease she knew only too well, having once fallen prey to it at the hands of another man who knew how to wield his charm and allure.

She looked away from his face and down to his hands.

“Nice-looking Zodiac,” he said. “But you couldn’t have come up from the bay. It’d take you half a day with that small motor. You put in somewhere south of here?”

An observant man. Usually she liked that type. She tried not to be dazzled by his near perfect physique and a face that was more handsome than any man should be allowed. It was distracting. And dangerous. That she also knew from experience.

“I might ask what you’re doing here,” she said, deflecting. She eyed the Zodiac, assessing another approach to freeing it from the mud.

“Eating,” he said with the same dazzling smile.

A wise guy. From his polished American accent and fine clothing, obviously a very wealthy and well-educated wise guy. But he didn’t have the body of a businessman.

He grinned and waved the sandwich at her.

“There’s a great deli about two hundred feet from here. Can I buy you a sandwich? You look like you could use one.”

She dragged her hair away from her face. She’d love a sandwich. But there was a mile of river to sample between here and the vineyard properties to the north. And she didn’t want to answer questions. He looked like the type to ask plenty of them.

“Thanks, but I have to get back.”

“Back where?”

Right. Not the cleverest of responses on her part.

“Back to, um…”

Jeez. Tracking down water samples had made her feel like she was in some sort of cheesy spy novel or something. This guy was just a guy having lunch near his local deli. Right. Dressed in expensive clothes and eating a sandwich by a really crummy spot in the river. She might be good at chasing down the mysteries of marine mammals, their lives, their health and the way the bigger picture affected them, but she was never much good at figuring out people.

“Back to work,” she said flatly.

“Where do you work? Can’t be around here.”

It was a simple question, a question she’d answered hundreds, maybe thousands of times. She hated to lie, usually didn’t have any reason to, but it was hard to ignore the small voice telling her to do just that. Maybe the sun had addled her brain. And she hadn’t been sleeping well. She’d read that lack of sleep could make you paranoid, make you read things into situations that weren’t there. She really should get more sleep.

“I work at the California Marine Mammal Center,” she said as she pulled her foot from the muck and edged closer to the Zodiac.

“The seal hospital near the Golden Gate Bridge?”

The Center was known for their quick response in rescuing injured marine mammals, doctoring them up and returning them to the ocean, but the work went far beyond that. Yet right now she didn’t feel like explaining.

She nodded.

“I’ve been meaning to get over there. For about ten years,” he said with a laugh.

“Evidently not a priority,” she said, trying not to like the sound of his laugh. “Or if it is, maybe you’re direction challenged?” She hadn’t meant to engage him, but his smooth manner was like oil on a hillside, and she just kept sliding along.

He sprang up from his crouch with a catlike, almost effortless, motion and took a couple steps down the path toward her. She stepped back and nearly lost her balance as her foot sank into the mud.

She fisted her hands against her hips, and he stopped walking.

“I heard you’re having a rash of seal deaths,” he said, suddenly serious. “Any clues as to what’s causing the diatom bloom?”

Her breath hitched in her chest. People in the Bay Area knew about the seal strandings; reports been all over the news. But most didn’t know about the diatom bloom or if they did, they didn’t get the connection. Maybe he was a scientist. But he didn’t look like a scientist. Scientists never had muscles like his.

“It’s too early to tell.” At least it wasn’t a complete lie. It was too early to tell. “I really have to be going.”

She turned and pushed her shoulder against the pontoon. Color crept into her face. She was stuck, in more ways than one.

“Here,” he said as he closed the distance between them. He bent down and put the sandwich on a rock. “Hop in. I’ll shove you off.”

She tilted her head and shaded her eyes. Maybe he could do it; he looked incredibly strong. His shoulders reached beyond those of most normal men. Only movie thugs and athletes had shoulders like that.

God, she was being ridiculous. Letting him shove her off was the best solution. Maybe the only one.

“Okay,” she said.

Their gazes locked, and she felt both trapped and held.

“I don’t bite,” he said.

There it was again, that easy, wide smile. She was really losing it if she could let herself be charmed by a stranger standing on a riverbank.

Before she could move away, he closed his hands around her waist and lifted her over the side of the boat.

“Straddle the pontoon on the opposite side,” he said as he released her. “Lean into it.”

The confidence of his tone told her he was used to giving orders.

He walked to the bow of the boat and stepped into the water. She noticed that he didn’t fall into the eddy pool. Maybe he knew this stretch of river very, very well.

She hung her weight against the pontoon and watched his arm muscles work as he gripped the bow line and levered his shoulder against the boat. With perfect control he tipped the bow down. The bottom of the boat sucked up off the riverbed with a sigh and a slurp, and with a firm, steady motion, he pushed the boat into the river.

“You might need this.” He grinned and tossed the bow line over the side. She caught it with one hand.

“Nice catch,” he said as he stepped out of the water.

Mud covered his expensive shoes and stained up his pant legs. He apparently didn’t notice or didn’t care.

Her hands shook as she started the engine. Only then did she remember she hadn’t thanked him. She waved and shouted thanks over the buzz of the motor.

“My name’s Alex,” he said as he waved and stared after her. “Maybe I’ll see you around these parts again.”

Not if she could help it. Maybe he wouldn’t notice that she was headed north, upriver to the vineyards. Besides, why would he care?

“There aren’t any marine mammals up that way,” he shouted with a puzzled smile. “No clapper rails either.”

She shrugged and looked resolutely upriver.

So much for not noticing.