A/N: So I'm all kinds of obsessed with writing post-ACOFAS Nessian right now. (I wish more people would write post-ACOFAS Nessian because I neeeeed that next book! How they were in ACOFAS was not what I was expecting! I feel like they're basically going to have to start over in the next book lol) So anyway, here's a post-ACOFAS oneshot that basically wouldn't end and probably could've gone on longer...

As Cassian made his way back to his cabin, with only the stars lighting his way through the darkness, he paused to stare at the first floor window of his cabin as he often did at the end of each day.

This evening, there were no lights on on the first floor. It had been a long, hard day of training for the Illyrians, so it was likely Nesta retired early. Even Cassian couldn't wait to crash upon his bed.

She'd been here in the Illyrian Mountains for nearly three months now and after much prodding, had only recently started going to training. She was learning quickly and had already made tremendous progress. At the memory of seeing her disarm an Illyrian male that morning, his heart swelled with pride.

So far, Cassian hadn't done any training with her. And when she was training, Cassian tried to watch but would keep his distance in hopes that she wouldn't notice.

Because she certainly didn't seem to want anything to do with him. It had taken much persuasion to convince her to come to the Illyrian Mountains in the first place, and she wasn't thrilled at all about the prospect of living in the same cabin as him.

Even though they resided in the same cabin, they didn't talk to each other much...only when necessary. And when they did talk, it was always a brief, clipped conversation that was riddled with insults.

He kept his distance in hopes of lessening her irritation though, in an attempt to make living in the Illyrian Mountains bearable for her since it was a bit forced on her. But he never stopped looking out for her.

Because he just couldn't stay away from her. There was just something about her...something that drew him in and he couldn't pull away.

There had been something previously developing between them. He'd been attracted to her since their first meeting. And despite her icy exterior, he felt there was more to her. From the way she had once wrapped his injured wrist...the way she desperately cried out to him so he wouldn't perish by the Cauldron's blast...to the moment she nearly died with him on the battlefield...there was definitely something more to her.

But that Nesta vanished after the war. Somehow she receded further into herself and was just an empty shell compared to who she used to be.

He wished the old Nesta would return because...he missed her.

When he walked through the threshold of his home, he tugged off his snow-covered boots to dry near the door. Before heading to the staircase, he paused to turn and look down the hallway that led to Nesta's room.

The door was closed as usual. And just like every night, Cassian silently wondered if he and Nesta could ever return to the way they were before Hybern's death. If there would ever be a instance where he could let her know that he was proud of her and she wouldn't bite his head off. If there would ever be a time where he could let her know how he felt about her and she would reciprocate those feelings…Feelings that wouldn't go away, despite all their bickering since the war.

With a sigh, Cassian trudged up the stairs to his room.

"AHHHHH!"

A scream erupted and reverberated throughout the house. Startled, Cassian instantly woke up from his sleep and shot up in his bed. It sounded like the sharp cries were coming from downstairs…

From Nesta…

Startled and frantic, Cassian quickly got out of bed and fumbled around in the dark for one of his daggers or knives that were lying upon a nearby table. Grabbing hold of the hilt of the first one he found, he tugged open his bedroom door, ran out of his room, and stomped down the staircase.

Upon reaching the first floor, be bolted toward Nesta's room, where the door was still closed, but he could still hear her shrieking from inside. "NESTA!" he shouted upon grabbing the door knob with his right hand. The knife still firmly held in his left. Not sure what he would find on the other side of the door, he lifted the knife to prepare to attack and pushed the door open.

Looking frenziedly around the room in the light of the candle-lit lanterns, Cassian didn't notice any intruders, but when he looked at the bed…

Amongst the tangled up covers laid Nesta, curled up in the fetal position and clutching her stomach. Her head was at the foot of the bed, while her feet were near her pillows at the head of the bed. Her body trembled as she let out another cry.

"Nesta, what's - " Cassian began to say, but stopped himself upon seeing a few spots of blood on the beige sheets near Nesta.

Oh.

He had had his fair share of dealing with Mor's cycles over the past few centuries. But he generally tried to avoid her the two times they annually occurred.

He'd completely forgotten that Nesta would be experiencing them...A strike of terror went through Cassian as he wondered how this would go.

Dropping the knife on the floor, Cassian went to the edge of the bed where Nesta's head was. As soon as he approached, Nesta's eyes widened and she glared up at him while wrapping her arms around herself even tighter.

"WHAT. ARE. YOU. DOING. HERE." she said through clenched teeth before he could even say anything.

"I live here," Cassian stated obviously. "Nesta, let me help -" he continued seriously, but was cut off.

"I DON'T WANT YOUR HELP!" Nesta barked at him.

"Nesta, I've dealt with this with Mor in the past. Let me -"

"I DON'T WANT TO HEAR ANYTHING ABOUT MOR," Nesta cut him off again.

Cassian gave her a perplexed look, but continued. "Let me help you! Do you want some tea? Mor usually likes to have tea…"

"I SAID I DON'T WANT TO HEAR ANYTHING ABOUT MOR!" Nesta shouted.

"Fine! What do you want me to do?" Cassian asked, exasperated.

"I WANT YOU TO STOP PRETENDING LIKE YOU CARE!"

Cassian gave her another puzzled look. "What are you talking about? I'm not pretending!" he exclaimed.

"JUST LEAVE ME ALONE," Nesta yelled. "It's what you're best at, anyway." she muttered angrily under her breath.

But Cassian heard her. He leaned down and rested his palms against the mattress, still confused by all that Nesta was shouting at him. "Care to elaborate?" he asked in a frustrated tone as he stared down at her.

Nesta groaned out of both annoyance and pain and turned her body so she was no longer facing him.

Cassian sighed. He then reached out to brush his fingers through her hair. "Nes," he said softly.

"DON'T CALL ME THAT!"

Cassian pulled his hand away from her. Looking down at the bed once more, he saw there were larger spots of crimson on the sheets where she had been laying before she shifted her body away from him. There were also spots on the nightgown she was wearing.

Without a word, Cassian left the room.

A few minutes later, Cassian returned to Nesta's room. Her screams of pain had decreased somewhat. Instead, she was whimpering as she clutched her blankets to herself.

But when Cassian slid his arms across the bed and under her body to scoop her up, Nesta began to shriek once more.

"WHAT ARE YOU DOING WITH ME, YOU SAVAGE BRUTE!" Nesta exclaimed as she wriggled in his arms. She tried to hit his bare chest, but Cassian wasn't phased since her hits felt like light taps. She was too weak from the cramps to remove herself from his grip.

"Calm down!" Cassian ordered, annoyed.

Nesta had no choice but to allow Cassian to carry her wherever he wished to go. She crossed her arms against her chest and closed her eyes, trying not to focus on the pain she was in nor on her current predicament with Cassian.

"THIS IS YOUR FAULT, YOU KNOW!" she shouted before mumbling. "If you had protected me like you promised you would, I wouldn't have been made into a Fae."

Struck by her words, Cassian nearly stumbled as he walked, but he caught himself.

He didn't say a word as he carried her down the hall to her bathroom, where he gently placed her on the sink counter. When her bottom hit the countertop, Nesta opened her eyes and placed her hands on Cassian's shoulders to steady herself.

"What..." Nesta said icily as she stared at him. "...are you doing?"

Cassian chose to ignore her question. "Where do you keep your underwear?"

Nesta's eyes bulged at the question. "Excuse me?!"

Cassian just grinned at her as he grabbed her hands and brought them down to the counter so she could grab the edge to hold herself upright. "Nevermind, I'll find them," he stated cheekily.

"You certainly WILL NOT, you pompous gargoyle!" she called after him as he walked away. If only she didn't feel so queasy, she would've ran after him and stopped him.

A few minutes later, he came back, with a pair of cream-colored underwear and a lavender nightgown in hand. Walking up to her, he tossed them into her lap as she glowered at him.

"Go ahead and change out of your bloody clothes. I've left some linens out for you to use. I'll change your bedsheets," he instructed her calmly before leaving the bathroom once more. Looking down at the other side of the sink, Nesta noticed the small strips of linen and a towel that had been left for her that she didn't realize were there when they first got to the bathroom.

Begrudgingly, Nesta slowly got down from the sink counter and slowly managed to clean herself with the towel and changed her clothes and undergarments.

When Cassian returned, he came up to her and stretched out his hands behind her back and her thighs, preparing to scoop her up in his arms again. However, Nesta thwarted that plan. She stuck out one of her palms against his chest to halt him.

"Don't treat me like some invalid," she reprimanded him as he brought down his hands. "I can make it back to my room on my own."

"And here I thought I was treating you like a queen, sweetheart," he replied casually. With a slight bow, he gestured for her to leave the room first. "Your chamber awaits."

A little wobbly, Nesta sluggishly walked out of the bathroom towards her bedroom, with Cassian following closely behind her. His attention to her was maddening.

"Do you have to follow so close behind me?" she spat. "Your breath smells. I can hardly breathe."

"I think it's really my strikingly good looks that are leaving you breathless."

"UGH! You're such an egotistical, overbearing -"

But Nesta was unable to finish her sentence, as a jolt of pain through her body sent her crumpling to the ground right as she turned into her room. As she squirmed, Cassian instantly reached out to scoop her up in his arms.

He carried her a few steps before laying her down upon the mattress. With both his arms beneath her back, he leaned over and whispered in her ear. "If you wanted to bring me closer, all you had to do was say so, sweetheart."

His breath tickled her face, sending her pulse racing unwillingly. Nesta narrowed her eyes at him as she prepared her retort, but another burst of pain shot through her. The ache was so strong that a few tears escaped Nesta's eyes. Out of pride, she turned her head to the side with the hope that Cassian wouldn't notice.

Pulling his arms out from under her, Cassian briefly left the room, but quickly returned with a stack of blankets. Laying them at the edge of the bed, he pulled them off one by one to cover her. Nesta's body froze when she felt the the warmth of the blankets surround her. Did he warm the blankets by the fireplace for me?

"What are you doing?" she asked him sternly.

"Comforting you in your time of need," Cassian said a little too gleefully for her liking.

"You know very well that - " Nesta began to reply indignantly, but stopped when Cassian placed his hands along the sides of her face, causing her to look up at him. His touch was so soft and gentle that she momentarily forgot to breathe. Moving his thumbs below her eyelids, he wiped away the tears that Nesta had failed to hide.

"Stop it," she feebly and quietly requested. "Why are you doing this?"

Cassian shifted his hands so one of them was now running through her hair along the side of her face as he gazed down at her. "Because you shielded my body with your own and refused to leave me when I nearly died in the battle against Hybern."

The mention of that moment she had long tried to forget made her go still.

"Don't talk about that," she ordered through gritted teeth as she turned her face away from him.

"Why not?" Cassian asked her gingerly, honestly wondering why she didn't want to discuss the precise moment he had thought about every day since it occurred.

"Because it didn't mean anything! I was clearly caught up in the moment and was out of my mind during that stressful situation. It meant nothing."

"Well it meant something to me!"

"All it did was show much of a liar you truly are," she answered seriously.

The hand Cassian had been running through her hair stopped. "What do you mean?

"Don't play dumb with me," she rebuked him while shifting her body from the discomfort within her body.

"I honestly don't know what you're talking about," he stated seriously.

"I don't want to talk about this right now," she replied in an agitated tone.

"But all you've done since that day is NOT talk about it!"

"Because I don't intend to ever talk about it!"

Cassian grunted out of annoyance. "For once, will you please just be honest with me and talk to me? Enough of these games!"

She looked back at him. "Well, I am honestly telling you to leave me alone and get out of my room."

"No," he said, standing straight and crossing his arms against his chest. "I refuse to go until you talk."

"You obstinate, infuriating bastard!"

"Oh, I'm obstinate and infuriating? You should take a look in the mirror."

Nesta scowled at him. "Fine. Then you're going to be waiting there for eternity because I'm not talking about it," she remarked as she turned to lay on her side, facing away from Cassian. Still writhing from the pain that Cassian somewhat distracted her from, Nesta closed her eyes and attempted to fall asleep.

But then she felt something press upon the bed behind her. Her eyes shot open and she flipped her body around to find Cassian laying down in the bed beside her.

"What do you think you're doing?"

"Well, if we're going to be here a while, I might as well get some sleep," he stated while pulling one of the quilts over his body.

"No. Get out of my bed!" she exclaimed and started swatting as his chest, but it was like hitting a block of steel. With Cassian's aggravating behavior, the threat of old feelings surfacing, and the vicious menstrual cycle currently raging through her body, Nesta let out a scream that evolved into whimpers.

"There's some tea on the stand beside you," Cassian told her gently. "It might help soothe your stomach. I used the herbs that Elain had grown."

Nesta turned and squinted at the cup of tea that sat there. It didn't look like it was steaming. "It's cold," she remarked sardonically.

"If you weren't so busy screaming at me, I would've been able to tell you about it sooner," he said with a slight edge to his voice. "But I'll make you a new one," he said, his voice softening. He peeled the quilt off his body and headed toward the kitchen.

She closed her eyes, hoping this wave of nausea would pass quickly, and pulled the blankets tighter around her to bask in their warmth. She had hoped she could fall asleep, but the cramps weren't making it easy.

A few minutes later, the heavy footfalls against the creaky floorboards signalled Cassian's return. Opening her eyes, she found Cassian standing beside the bed, holding a steaming cup of tea on top of a saucer.

"You'll need to wait a minute or two so it doesn't burn your tongue," he informed her.

"Give it here," she told him as she slowly sat up. "I'll just blow on it."

Cassian smirked as he handed her the cup and saucer. "I love it when you talk dirty to me."

"Ugh!" Nesta exclaimed before blowing on her tea.

As she took a sip, Cassian kneeled on the mattress to grab the pillow behind her and propped it up against the headboard. "Here, lay back."

"Cassian, enough with this act. Stop pretending to care."

"I am NOT pretending!" Cassian's rage returned as he stood back up.

"You're only trying to take care of me because it's what your High Lady ordered you to do."

"If that were true, then all I would've done was make you tea and leave you to fend for yourself."

"Then why the hell are you here?!"

"Gods, Nesta! I often wonder why I put up with this irritating nonsense of yours. But I can't keep those images of you covering my body on the battlefield and you calling for me to save me from that Cauldron's blast out of my head! You didn't leave me alone to fend for myself then, so now I foolishly can't stay away and have to deal with this insanity!" he yelled back.

"Well I'm surprised by that, considering you were able to keep your distance from me those days and weeks after the war…despite claiming that your only regret was that we didn't have time!" she fired back snobbishly.

Cassian froze. "Is that what this is about?" he asked while staring at her blue-gray eyes.

Instead, Nesta moved her focus to the cup in her hands. "I should've known it was just something you said in the moment. I was a fool to believe it was true."

"It was true. It is true!" he fired back loudly. "I still regret it. But you keep pushing me away, so I started assuming that you didn't care to spend time with a low-born bastard like me."

After setting the cup of tea down on the stand beside her, she pointed her forefinger up at him. "I didn't see you for weeks after the war! You didn't first try to talk to me until over a month later!" she shouted.

"I thought you needed time!" he exclaimed.

Nesta shifted her body so she was on her knees and elevated herself so she could meet Cassian at eye level. "I was drowning! I needed you and you weren't around!" Nesta pressed a finger to the middle of his chest.

"Well, I guess I screwed up then! I thought I'd give us both time before we figured out whatever this was!" He gestured between the two of them. Taking a few deep breaths, he let his anger cool. "I...I needed some time," he continued quietly. "To myself. The war took its toll on me. So many of my men had died. And I thought that you needed time too...Then when I did try to talk to you, you shut me out. I guess I was too late."

"You, and Feyre, and your happy little Circle...you all just seemed too ridiculously happy after all we had gone through," Nesta replied in a softer tone.

Cassian reached out and cupped her face. "It was all a front. We were trying to be happy so things would feel normal." He sighed as he rubbed her cheek with his thumb. "I've failed you in so many ways. I should've been able to stop the king from turning you into a Fae. I should've been there for you sooner. I'm so sorry."

Nesta stared at him, tears welling up in her eyes again. Damn period making her easily emotional…

"How come you don't hate me?" she whispered.

"What?"

"I've said so many awful things to you, and...you're still here."

"Well, you don't have a lot of good moments...but you do have them," he said with a cheeky grin as he rubbed her cheek with his thumb again. "I just keep reminding myself that you're grieving, and I keep hoping that the woman that was on the battlefield with me will return."

"I don't know if she will," she truthfully replied without any bite in her words. She still had moments where she felt empty inside. But training with the Illyrians lately...it had helped give her some purpose...

"I think she will," Cassian said with a small smile. Nesta's face scrunched up and evolved into one of discontent. She brought up one hand to cover her mouth, and the other clutched at her stomach.

Concern flooded over Cassian's face. "What's wrong?"

"I think I need to go to the bathroom."

In a swift motion, Cassian gathered her in his arms and got her to the bathroom in record time. Setting her down on the cold, tiled floor beside the toilet, Cassian immediately lifted up the seat before kneeling on the floor beside her. Running his fingers through her hair, he pulled her hair back and held onto it. She grabbed hold of the toilet bowl to lean over it and retched.

When she sat back up, she looked over at Cassian. "You don't need to do this," she said weakly.

"I want to. I want to be here for you."

If she wasn't so sick and about to retch again, Nesta might've smiled for the first time in a while.

When her stomach finally settled a bit, and Nesta rinsed out her mouth, Cassian carried her back to the bedroom. This time, Nesta didn't fight him on it.

The pain in her body subsided, and exhaustion overtook her. But if this cycle was anything like her last one, she knew the cramps would come roaring back to life in a few hours. She would need to sleep while she could.

After Cassian put her down and pulled the covers over her, Nesta looked up at him. He had been about to walk away from the bed, but then he paused. "Is there anything else you need? More tea? Extra blankets?" he asked.

Nesta sat up in the bed and disregarded his question. "Where are you going?"

"Back to bed," he answered simply. "Is there anything else you need before I go back upstairs?"

Nesta swallowed. "You," she breathed.

His eyes instantly found hers. "What?"

Nesta reached over to grab one of his hands to yank him back into the bed. Cassian gave her a perplexed look.

"What are you doing?" he repeated the question she had asked him multiple times earlier.

"Bringing you back into bed, you dolt."

"I thought you wanted me to get out?" He said with a smirk. "I guess you couldn't resist my charm after all."

Nesta rolled her eyes, but didn't deny it. "Don't go," she whispered. "Please...stay."

Cassian sat on the bed beside her and interlaced his fingers with hers. "I'm not going anywhere."

Nesta beamed as Cassian laid down beside her. He closed his eyes once his head hit the pillow.

"Thank you," she said softly, referring to all he had done for her that night. Turning her body away from his, she wrapped Cassian's hand around her side so his chest was against her back. Cassian nestled his face in her hair.

"Guess my breath doesn't smell that bad, or else you wouldn't let me sleep this close to you."

Closing her eyes, she hugged Cassian's hand against her chest. "You still smell, but I'm going to need some bones to break for relief when the cramps start again." She smirked as she tightly squeezed his hand.

"Goodnight, my sweet Illyrian warrior," he told her before kissing her temple.

"Goodnight, my egotistical, overbearing, savage brute."

A/N: Hope you liked it! Originally, there was going to be a kiss in this one...but I took it out because it felt too soon. So I may have to put a Nessian kiss in another oneshot...haha. And if there are any post-ACOFAS Nessian scenarios you'd like to see...let me know and I just may write it! I'm on a Nessian writing-high!