A/N: First a big thank you to Amanda Tapping for confirming our suspicions of the Sanctuary having a pool and for telling us it has a waterfall. Secondly, a big happy birthday to my friend Criss who this story is for, as well as to Nikola Tesla, who both share a birhtday of July 10th. This is all Teslen all the way. All reviews welcome. hope you enjoy it =]

She had the only key to the pool. When he had decided to move in, this turned out to be quite the problem. Nikola had always gotten up very early to swim his 27 laps. The first day he tried to do this he wound up wasting an hour trying to find Helen to get the key from her. He finally found her asleep in her room, or half asleep as the loud bang of him bursting open the door had awoken her. This left not only her but him in a foul mood for the rest of the day. That evening she had gone to him in his laboratory and they had worked out a system. Each night before she went to bed she would bring Nikola the key to the pool in his room. If he was not there she would leave it on his bed side table for him to retrieve when he went up to put his swim trunks on. Then before going to his lab for that day's work, Nikola would bring the key to Helen's office and either hand it to her personally or put in the upper left hand drawer. And so the two had fallen in a routine. A routine that in fact, often lead to late night chats and frequently shared brunches.

The morning of Nikola's birthday was no exception. He did not particularly care to think about the fact that it was in fact July 10th again so soon as it meant now that he was indeed a year older. This meant, however, that he needed to be more diligent about his physique; hence his up keeping of his ritual 27 laps. Not to mention it had brought him his rather exciting routine involving spending a lot of time Helen. However, this was not a day he wanted to spend with anybody. So the night before he had slept in his lab to avoid seeing Helen in his room and planned to return to the key to her when he was certain she wasn't in his office.

At least that was his plan right up until he found the note on his bed side table.

Nikola,

You will find the pool door unlocked this morning.

Helen

PS. Happy Birthday

Perplexed Nikola returned to the note to its former spot on the nightstand and then went about preparing for his swim. He thought it over on the walk down to the pool. As promised the door was unlocked, in fact it was slightly ajar so that the faint splashing of the waterfall wafted out. Slipping inside, gently shutting the door behind him he saw all the familiar sights. The gorgeous mosaic tiles, expansive pool and thundering falls. But, there was also something he had not expected to see.

Helen Magnus was seated on the nearest edge of the pool. Her luxurious legs were swinging slightly in the water, and once and awhile she would lift one or the other straight out of the water and admire her pedicure. Leaning back her hands planted firmly behind her, her body was extended and from where he was stripping down to his swim trunks Nikola could see more of Helen than he'd ever dreamed he could, all thanks to the bikini she was wearing. As he approached Nikola knew before she turned to look at him that the blue of the bikini would make her eyes stand out even more than usual.

She had known he was there for a while before he walked over to her. She'd heard his slight gasp at finding her there, dressed like this, and it made her smile smugly that she still had that affect on him. Turning to smile a greeting at the sound of his approaching footsteps Helen found that he still had that affect on her. His body was as lean and muscled as ever. She managed somehow to not stare and say,

"Glad you finally decided to come join me."

"I hope I have not kept you waiting," Nikola replied, taking a seat a hair's breath from her.

"Oh not me, just the wine," Helen winked producing a bottle of wine and two glasses from her other side, "I was beginning to worry about keeping this cool enough for your liking."

Nikola gave her a mischievous grin and taking the bottle examined it.

"This is you're oldest and best bottle if I remember your wine cellar correctly…"

"It is indeed Nikola," She nodded to him and he began pouring her a glass, "Only the best for the birthday boy."

At this Nikola sighed a little and, handing Helen her glass half full muttered,

"Must we really discuss that?"

Helen laughed while he poured his own half a glass,

"Of course we must. It's not every day one turns 154!"

Nikola put down the bottle of wine, and raised his glass to her,

"To eternal beauty,"

Holding back a blush she clinked her glass to his saying,

"To your birthday."

The two sat in silence, sipping their wine and slipping looks at the other. Helen finished her glass first, placing it empty beside her she scooted forward to the edge of the pool. Once there she gently lowered herself into the pool. They were seated at one of the deeper parts so she had to tread water since her feet didn't touch the bottom. Then she pushed off from the wall, ducking her head into the cool water to swim out a little ways. Nikola watched each motion greedily from over the top his glass. When Helen slowly emerged from under the water a yard away from him he grinned hiding it by finishing off the last of his glass. She was teasing him and he knew it, it was just like old times. They went back and forth, flirting and teasing but never going anywhere with it.

Just then she called to him,

"Care to race me to the waterfall?"

Nikola placed his glass next to hers, then pretended to eye the short distance from where they were to the waterfall.

"I don't think so."

She swam a little closer saying,

"Afraid I'll win?"

"Quite the contrary. I know I'll win."

As he said this she swam up and delicately took hold of his legs to keep afloat. She grinned up at him replying,

"Nonsense. You're scared you'll actually lose to me."

Nikola put his hands on either side of him to steady himself not only as he leaned forward to respond to Helen but also to steady himself from the delicious feeling of her fingers digging into his lower thigh.

"And what gives you that false impression?"

She lifted herself out of the water just a tiny bit more, bringing herself closer to him, smiling,

"Because you're old now."

Nikola lifted an eyebrow at her. He swatted her hands from his legs and slid into the pool.

"On your count," he said to her.

She nodded,

"One…two…go!"

They splashed off. It was a close contest, but all those years of 27 laps paid off. Reaching the cascading water first he found that the water was shallower here, coming only to his waist. As he stood up, Helen arrived. She came to stand directly in front of Nikola who was standing facing waterfall. The water thundering down, splashing up to slide down their bodies, Helen leaned into Nikola's ear,

"So what prize do you claim for winning?" she asked in sultry tone.

Without a seconds hesitation Nikola turned his head and took her lips, cradling her head in one of his hands. This time, when Helen grabbed Nikola's arms, it was not to pull away, but pull closer. There was no tingle of electricity this time, and she did not miss it as this kiss was better. She allowed him to deepen it quickly, allowing his asking tongue inside her mouth. They could taste the wine on the others mouth. She pressed her body to his, sliding her hands through his wet hair. He went to pull away but she bit his lip. She felt the growl rumble in his chest before he reclaimed her mouth, his hands now on her waist forcing to step backwards until she passed through the waterfall and her back hit the wall behind it.

His hands grasping her arms, his waist leaning on hers, he kept her pinned beneath him, he pulled back to hover just above her. Helen gathered what little breathe she had left to ask in a suggestive tone,

"Is that the prize you wanted? A kiss?"

Nikola raised his lips in that smile that showed off just one canine before lowering himself to her ear.

"No," he whispered in something just short of a growl, "I want to hear you scream my name."

Helen shivered slightly with anticipation and turning her mouth to his ear nipping it gently replied,

"Only if you can make me."

Then his lips were mingling with hers again. His hands slid around to her back, one leaning her forward while the other deftly undid the tie of her top. Gently returning her back to its prior spot his hands then went to the back of her neck, and undid that rather loose knot as well. Her top bobbed away on the little waves created by the force of the waterfall and Nikola began to slowly kiss in a direction leading away from her mouth. When Nikola brushed a kiss against the pulse on her neck Helen had a brief second of worry that somebody would waltz in for a swim and find them here. But then she remembered the door locked to the outside automatically upon shutting and that the only key was beside the bottle of wine she'd brought down, not to mention that it was unlikely that anybody would be able to distinguish their moaning from the noises of the waterfall splashing down all around them from the other side of that door.

So it was that when Nikola's fingers began making the motions on her one breast that his tongue was doing to the other, Helen let out a particularly vocal moan. Nikola was not too pleased with this result. He drew himself to his full height, and gave Helen a playfully reproachful look.

"That was not my name," he whispered into her ear in a tone a mix of scolding and threatening.

She returned his look and his comment by shifting her weight in such a way that her hips rubbed forcefully against his growling,

"That's because you have not done anything to deserve hearing it."

Nikola had always loved the amount of control she had. He'd even fantasized about a day when he would give her complete control over him. But it was not this day, this day he just wanted to break her. And he knew just how to do it.

He kissed her, slowly, taking his time in deepening it. After her hands had wrapped around his neck he carefully began caressing his hands down her body, appreciating every patch of bare skin, before coming to rest them on her hips. He waited a few moments, returning all his focus to her mouth before dragging one finger to leisurely skim across her skin just above her bikini bottom. She moaned a little at his touch, shifting her hips to press them against him harder. He again waited before moving again. This time his hands whispered their way up her thighs. After another second he simultaneously abandoned her mouth and hooked his fingers under the fabric of her bikini. Then he lowered it down from her hips, down her legs, off her body letting it float away, placing kisses on her left leg on the way down, and on her right leg on the way up.

Once he was standing again standing the waterfall pounding his back, he paused to take in the sight of the most beautiful woman he had ever known, the only one he had ever loved, standing there willing to give all of herself to him. As he returned to her Helen could feel that his erection was harder her leg. She took his mouth, ran her fingers through his hair and rotated her hips to let him know she knew and was ready. Helen groaned heavily as his hands suddenly gripped her thighs tightly and he spread her legs so he was now standing between them. Helen slid her fingers under the waistband of swim trunks, eager to remove the last barrier between them but quickly found Nikola's hands wrapped around her wrist, holding them above her head.

Keeping her hands pinned there with his left hand, he lowered his right hand into the small space between the two of them. He places a loving kiss on the pulse of her neck while sliding two of his fingers inside her. Nikola felt the reverberations of her moan on his lips and as her eyes fluttered shut and she arched her back at the gentle but rough way he was handling her, he smiled to himself.

"Nikola, please," Helen groaned her plea to him as his hands suddenly abandoned her.

"I see I must have finally done something right," he crooned in a slightly mocking tone.

Helen did not want to risk opening her mouth to reply so she simply bit her lip, nodding her head slightly and opened her eyes to meet his. Next thing she knew Nikola's hands had grabbed her thighs, lifting her out of the water. He thrust into her so roughly that her back was pounded against the wall and she let out a startled but satisfied moan not only at the roughness but at the feel of him buried deep inside her. His next thrust was a hard as the first, and it came just as she managed to properly wrap her legs around him. Helen met his next thrust with equal force, clenching her inner muscles around him, and he groaned heavily. His fingers gripped her thighs tighter and her heels dug into his back. They could feel each other nearing their climax.

And soon after when they came together, Helen screamed his name. Not because he wanted her too and not because it was his birthday. But because she wanted to let him know that he had just given her the best orgasm she had ever had, and that she wanted more.

Nikola gently let Helen down to stand on her own, and she held onto his arms resting her forehead against his, both breathing heavily. After a moment Helen leaned in and kissed him gently. Pulling back she smiled to him mischievously,

"How about I show you the hot tub now?"

"Alright but first," he kissed her forehead before moving away, "I think I want some more wine."