Notes: /Title taken from Njord by Leaves' Eyes./

So! This has been in the works for quite a while now, but it's actually rather different from the original idea that I had. The backstory of it will unfurl as it goes; for now, all you really need to know is that I don't know as much about merchant ships in the 18th century as I wish I did. I hope this is enjoyable nonetheless. Feedback is welcome as always!

The sun had already set by the time everyone had finally gone inside. They trusted their Captain when he told them about the creatures that swam in these parts of the sea – he was the only one who had gone through it unscathed, after all – and there was no shame in having the common sense to protect themselves when they needed to.

Alec, however, hadn't followed their example. As the only one immune to the sirens and their calls, it was his duty to try and guess how long it would last this time; if he would have to tell his men to keep hiding well into the morning on the whim of the monsters.

The trouble was, of course, that they didn't resemble monsters at all. Alec had seen that easily enough when his sister had fallen in love with one of them and even if the circumstances back then had been different – the siren in question had been captured by a circus and had only met her outside of the water, when Isabelle had decided to free her – he was still suspicious every time he saw her. He could tell that she wasn't using her voice to control her, but unlike him, his sister was all too susceptible to their magic. Some of the doubt would always linger, Alec had resigned himself to that, even if he would never say it outright.

Instead, he'd let them both be and had left on his next voyage. It had been months in the planning and the preparation alone had taken just as long and he would not let it all go to hell just because of the dangerous territories they had to pass through.

He didn't even need to do anything to chase them away, really; he just had to make sure they stayed at a safe distance from everyone else. He sat down on one of the benches near the main deck and let the cool breeze that always followed the sunset during summer wash over him, gentle and almost soothing despite the undeniable tang of magic in the air.

Soon enough, the silence around him was broken in a way that was almost expected – anticipated – by now. The wind carried faint laughter with itself this time and Alec smiled despite himself.

Much to his surprise, the sirens didn't seem to feel any resentment towards him despite the oddity of his situation. If anything, they liked him for his ability to have an actual conversation with them and Alec indulged them occasionally out of boredom more than anything else. The tales they told were always intriguing and never failed to fascinate him and with time, he had become used to their presence.

That didn't mean that they couldn't still surprise him on occasion; not at all. It was going to be one of those nights, he realised rather abruptly – before he had even had the chance to try and enjoy his peace and quiet, his attention was drawn to the hands gripping the edge of his ship, going white with the effort as their owner tried to come into view.

The face that followed was nothing like any of the ones Alec could have expected. It was distinctly male and really, that was just the tip of the iceberg.

The siren's hair was pushed to the back, still dripping wet, the sides of his head shaved like a pirate's and Alec would have almost thought him to be human if it hadn't been for the gills that quickly disappeared into his skin now that he was above the surface, and the haunting combination of the colours in his eyes. He was as beautiful as the rest of them, only somehow more so; the strange magnetic power that Alec had only ever heard stories about suddenly clicking into place.

"Hello," the siren said at last, voice still raspy in a way Alec knew came with the use of his lungs for the first time in a while. "You must be Alexander Lightwood."

It was typical for those of the Fair Folk to use full names with the sole purpose of intimidating humans – the ones living outside on the surface were quite similar in that regard – but Alec didn't flinch. "I am."

"You would have to be, to still be out here." The man pulled himself up even further until his elbows were resting where his hands had been and Alec reached for his sword on reflex despite the siren's nonchalant tone. "And I heard stories about you and Isabelle; that you're very similar in looks. Are you aware that your sister is keeping mine hostage?"

The accusation was enough to bring Alec out of his stupor and he stood up to near the creature that had suddenly invaded his territory. He knew what this was about and some part of him had expected it to happen. "She did nothing of the sort," he said, voice wary as he approached. "Clary was captured by someone else— by a travelling circus. Izzy was the one who freed her. She stayed on her own free will; she even promised to visit her home sometimes. Perhaps she will the next time Isabelle is at sea."

A moment of silence followed and Alec suspected that the man was trying to tell if he was lying. They couldn't always tell, but their guesses were usually close enough.

"Perhaps." The siren didn't want to let his surprise show, it was clear as day, but he didn't move from his place. "She must be very unusual, your Isabelle, to want to keep a siren around. And so are you, if the rumours are to be believed."

"And what rumours would those be?" This was nothing like the conversations he usually had with the sea monsters in these parts and he should have chased him away already, but Alec had always been curious when it came to what lived in the depths. Plus, what harm could it do? The man couldn't affect him either way.

"They say that you can survive a one of our songs." The siren's mismatched eyes were assessing him carefully even in the slowly descending dusk of the evening. "That you can refuse our call, no matter how tempting the offers you receive are."

"It's just words," Alec shrugged, trying to shake away the feeling that the scrutiny was giving him. "I could never understand how anyone could be tempted at all."

"But your sister is, isn't she?" There was a calculating gleam in the look he received now. "But all of us, too, men and women alike."

"I wouldn't know," Alec admitted. "I had never met a male siren before, and neither has she, as far as I can remember."

"You have now," the man informed him cheerfully and Alec bit back a sigh. They always understood everything so literally and he had given up trying to explain how the majority of the sailors spoke a while ago. "I'm Jace."

"Hello, Jace." Alec extended his arm for a handshake, driven mostly by habit, only to have the siren's eyes widen in alarm as he pulled away. "What—"

It was no use; before he'd even attempted to finish his sentence, there was a loud splash and just like that, Jace was gone.

o.O.o

The next day, there was no wind. It was quieter than Alec ever remembered it being and trying to make any progress in this kind of weather would be fruitless, so they didn't even try.

It was a long day. Without the usual movement, the surface of the ship was scorching hot and there was no way Alec would try to make his men row forward when he knew just how painful it would be. No, they'd just have to wait this out; no reason to resort to solutions that would drain their food and water supply much more quickly. They weren't transporting anything perishable anyway.

And so they waited. In the hottest hours of the day, everyone but Alec had retreated to their respective cabin to seek refuge from the unforgiving sun while he paced back and forth, too lost in thought to get any actual rest.

This was his fault, there was no doubt about it. After Jace had vanished last night, no one else had appeared – highly unusual for these parts of the sea. In fact, it had been so quiet that he had managed to get a full night of sleep even without going back to his bed and Alec couldn't help but wonder what it was about his behaviour that had offended Jace and his kin so much. And if they really were offended, why did they want to keep them here? They could have summoned a storm instead and, if it was vicious enough, it could have drowned them all. What kind of scorned creature wanted to keep the source of the offence so close to their home?

Alec got his answer later the same day, minutes after he'd started dozing off while leaning against his wheel. It made sense that a siren would choose a time when his mind was so hazy, he couldn't help but notice; they were always ready to use anything they could to their advantage.

He thought Jace to be a dream at first, mainly because he couldn't see him. He could hear his voice as if floating from above, scattered in the air around him like the specks of water that came with sailing, but unlike the water, he couldn't pinpoint where it was coming from and it was more frustrating than he had expected it to be.

"I thought you said it wasn't Isabelle's people who kidnapped my sister."

"It wasn't them." The words came out mumbled and indistinct and Alec cleared his throat as he forced himself to wake up fully and open his eyes. "I told you; there was a circus—"

"And how can I be sure that you're not a part of it?" Jace was in his field of vision now, leaning against the side of the ship once again, yesterday's curiosity his piercing gaze entirely replaced by hostility.

"Why would you even think that?" Alec heavily suspected that the fact that he'd been asleep until now was making this even harder than it needed to be, but he still had to ask. "I haven't done anything to you."

Jace frowned, perplexed. "I thought— the day Clary was taken, she was talking to a sailor. She tried to enchant him, but he had some kind of potion that was supposed to protect him and he just— he pulled her up on board of his ship once she came close enough. We never saw her again."

So this was what it was all about. "I wanted to shake your hand," Alec said, something a bit hysterical bubbling up behind the words despite his best efforts. "It's what people do when they meet someone new. Has no one ever told you?"

"No one lingers around enough for me to learn their customs." Jace seemed vaguely embarrassed now, even if he wasn't letting it show fully. "They either run or get affected by our magic. How was I expected to know—"

"You could have said something," Alec noted, still inordinately amused by the rather surreal exchange. If anyone from his crew saw him like this, they would have considered him mad and he couldn't be sure that they wouldn't be right. But there was something bothering him, something he couldn't really ignore, and, "I wanted to tell you last night— Clary told us all about you. I didn't realise when you said that she was your sister because she refers that way to all of you, but when you said your name... She misses you. She even wanted to come with me this time around so that she could visit, but we weren't sure if it would be safe for her to leave the manor yet."

"Manor?" Jace repeated. He'd come even closer now, emboldened by the unspoken peace offering.

"It's a house." Alec didn't have the faintest idea what kind of homes the sirens had, but they had to have something, right? "A big one. It's— It's got gardens and ponds and there's more than enough space for her, but she says she misses the sea."

"Of course she does. You must bring her with you when you come next." Jace's tone was imperious now, almost like an order. "She was captured once, but she won't let it happen again. Tell her—"

One of the doors behind Alec's back creaked open and he didn't get the chance to hear the rest of the message or to promise to deliver it; Jace's reaction to the sudden change of the circumstances as strong as it had been last night.

Distantly aware that he was being spoken to, Alec stared after him. For an instant, he was sure that he'd caught a glimpse of something golden and gleaming; something that resembled a tail far too much to be anything else.

o.O.o

For the first time in years, Alec was at a crossroads. The issue with the wind still persisted, the men were starting to wonder whether there was a reason for it and while he was painfully aware that he couldn't tell them anything, it was just so difficult to keep quiet. They admired him for his abilities as a leader and for his immunity to the sirens and their powers – even the ones he kept on board without any closeness from either side respected him because of his father's name – but everyone would draw the line at actually trying to communicate with the creatures lurking below the surface, there was no doubt about that. No one would stand for it, not even if it got them out of their current situation.

And so naturally, while still unsure whether it was the right choice to make, Alec tried to orchestrate another meeting. He waited until everyone else got tired of staying out in the heat anticipating a change in the weather; until it was so late that he was sure they were all asleep already. When that time finally came, he wandered out on the quarterdeck again and took his place, settling in on the spot where he spent the nights that consisted of watching over the ship.

What he wouldn't have given to be able to tell Izzy about all of this. She was frighteningly fascinated by the sirens, always had been, and it was strange given how easily affected she was by them, but Alec had got used to it a long time ago. She would be thrilled by all of this, and she would share it all with Clary, and then maybe—

"Are you heading home, Alexander?"

Alec didn't jump – he was always alert, especially when on duty – but he still couldn't mask his surprise entirely at the sound of Jace's voice. "Yes. Why?"

"I would like to follow you there, if you wouldn't mind." He didn't give Alec the time to say that he would, in fact, mind, likely suspecting that outcome and preferring to cut him off beforehand. "No one else has to know, please. You don't know when your sister will travel again, and I don't know when it will be safe for Clary to swim or stay on land as she pleases. If you have really met her, you would know that we can disguise ourselves as human if we need to. No one will even notice me."

This was a disaster waiting to happen. Alec was used to thinking things through, calculating every possible outcome of every decision, and there wasn't one direction that this could go into that wouldn't be potentially dangerous for everyone involved.

But at the same time, if their places had been switched – if this had been about Isabelle – he would have wanted the exact same thing. He couldn't refuse. If he did and something did happen to Clary in the meantime, he would never be able to live with the thought of it. He had seen enough to be aware of just how similar the sirens they were to them and there was no way he was going to ignore a plea for help when he saw one.

"I can't be responsible for you," he warned, trying to stay stern even as Jace's face lit up. "You'll have take care of yourself no matter what happens, do you understand?" A quick, eager nod. "And you can only stay here when I'm around. You can't appear around the ship otherwise."

"Understood," Jace said and even if the agreement was all too quick, the gesture that followed – a hand extended towards Alec, as if this were a business deal – was enough to prove just how serious he was. "I'll find a way to repay you for this."

"You don't need to," Alec hurried to say, not too willing to become familiar with the kind of rewards sirens opted for. "Just don't get in my way."

It wasn't an overly encouraging start, he admitted to himself, but then again, it didn't need to be. It was a promise and as long as that was enough for both of them, nothing else really mattered.