A/N: My first attempt at a Heronstairs AU. Nothing too complicated, just modern day and all human. Alternating perspectives. Inspired by the songs mentioned in it. Please comment and let me know what you think!

Something felt wrong when Jem walked into the apartment, exhausted. It had been a long, awful morning at the doctor's, then class, then rehearsal. All he'd wanted to do all day was come home and curl up on the couch with Will.

And possibly work up the courage to make use of the ring box in his pocket.

Church came up to him, weaving between his ankles and nearly tripping him as he shut the door.

"Move, cat," Jem chided fondly. "I don't have treats for you." Despite his words, he scooped up the cat and stroked it gently.

"What do you think, Church?" he whispered. "Is today the day? Am I going to ask him?"

Church meowed softly and kneaded his claws in Jem's shirt. Jem laughed and set the cat back down.

"I'll take that as a yes."

This was all normal. But Will, who should've been home by now, was nowhere to be seen.

Walking down the hall to their room, Jem called softly. "Will? Are you here?"

There was no answer.

Beginning to worry, Jem opened their bedroom door, meaning only to set his violin case down. He stopped short when he opened the door.

A wave of powerful disbelief and betrayal crashed over his head, anger bubbling somewhere deep below the surface of his emotions.

Because there, in his own bedroom, stood his boyfriend of four years, looking horribly guilty. His hair was a mess, shirt was off, and pale lipstick marks left an accusing trail down his chest. Behind him, trying to escape out of the window, was some dark-haired girl, equally disheveled. Her hair was a tousled mess, there were obvious marks down her neck and shoulder, and she was dressed only in an oversized shirt of Will's and what looked like a pair of underwear... Holding her bra in her hand as she froze halfway out the window.

"J-Jem," Will began, attempting to tame his hair. "I didn't think you'd be home this early..."

"Obviously not," Jem said, surprising even himself with the coldness in his voice. "I can see I'm interrupting something."

"N-no," the girl stammered. She looked oddly familiar...

Jem's eyebrows raised. "Tessa?"

She flushed, embarrassed. "Jem..."

Jem gave a humorless laugh. "Of course, Will, it would be her. Not just some girl, but a friend of ours as well?"

"I-I'm sorry," she stammered. "I'll just... Go..."

Jem shook his head. "Oh, no, don't leave on my behalf," he said, cold sarcasm lacing his voice. "I'll go."

"Jem..." Will began pleadingly, but Jem simply turned on his heel and left the room, the front door swinging shut abruptly behind him.

~•~•~•~•~•~•~•~•~•~•~•~•~•~•~

Jem walked down the streets of London, hands deep in his pockets. Heart heavy, he made his way to Blackfriar's Bridge. At this time of day, it was blissfully quiet.

He didn't think he could handle being around people just then.

Leaning against the railing of the bridge, Jem closed his eyes, trying to fight the silent tears slipping down his cheeks.

'Will was sleeping with someone else. Maybe just once, maybe regularly.'

Jem ran his hands through his hair and finally allowed the tears to fall freely.

'Will had feelings for someone else.'

This, he knew was true. Will was not one to use sex as a meaningless pleasure, despite his constant stories. For him, it was a sign of love and trust and desire.

It broke his heart to know those feelings were directed at someone else.

What had he done wrong? What had he done that he was no longer enough for Will?

Jem looked down at the river, stubbornly ignoring his morbid thoughts. Deep in his heart, he knew this wasn't something they could come back from. Not cleanly. If they tried, it would be a mess, for what was a relationship without trust? Jem had trusted Will with his love, but... perhaps that had been a mistake.

The sun set over the river, painting the sky colors as vivid as any Jem could imagine. As the night crept up on him, he tried very, very hard not to think about how much the inky blue looked like Will's eyes.

But he couldn't do it. So his mind went to Will's eyes, and his heart sank to the bottom of the river.

~•~•~•~•~•~•~•~•~•~•~•~•~•~•~

Will stood in his bedroom, ashamed, as the front door swung shut behind his boyfriend.

"Oh, crap," Will muttered. "What have I done?"

Tessa, cheeks flaming, quickly got dressed. "You need to go after him. I... I'm sorry. I'll just... go..."

Will nodded without saying a word and walked out of the apartment as quickly as he could, leaving Tessa standing behind him.

Outside, he wished he'd thought to grab a coat on the way out- the sun was going down and he was cold.

Oh, God. If he was cold, Jem must be freezing. He hadn't had a coat either, and Jem got cold extremely easily as a side effect of his illness. If he was feeling ill, he got cold more easily. And the colder he was, the sicker he felt.

His entire illness was just an unfair vicious cycle. Jem was too good of a person to deserve that.

'Jem is also too good of a person to have his heart broken,' the voice in Will's head whispered angrily. He shook his head and continued walking, looking for anywhere Jem may have gone. He wasn't answering his phone, and Jem was not one to go to someone's house if he was feeling down or out of sorts with Will. At times like this, Jem would be craving solitude.

Just as Will had begun to give up hope of finding him, a flash of silver caught his eye from the bridge. Will raced over, clumsy in his own haste, and slowed when he was a few feet from the silver-haired silhouette. His face was tipped up towards the dusky sky, and in the dying sunlight Will could see tear stains on his lovely face, shining accusingly.

"Jem..." Will began uncertainly.

Jem looked down from the skies and turned to look at Will directly. "How could you, William?"

The betrayal in his voice stung. "Jem... I'm so sorry... I have no idea what I was thinking..."

"Do you love her?" His posture had visibly tensed, as if preparing himself for the worst.

"James, I-"

"Do you love her?"

"No!"

"William, do not lie to me!" This was the extreme of Jem's temper, and Will stood in shame for having caused it out of heartbreak.

"I... yes. Yes, I have feelings for her, but they pale in comparison to my feelings for you, surely you know that," Will nearly begged him, trying so hard to erase that look from his angel's face.

"I thought I could put my faith in that. I thought, actually, that I could put my faith in you. But perhaps I was wrong."

Will felt a slight flare of indignation. "James, nobody's perfect-"

"I am not asking you to be perfect, Will, I am asking you to be loyal. And if you can't do that, then there's no way this can work." Jem's voice was shaking, and Will felt tears prick his own eyes.

Would this be the end of them?

"Jem, please... I made a mistake..."

"How long?"

Will had been dreading this question. "What?"

"You heard me loud and clear, William. How long has this been going on?" Jem's voice dropped to an almost inaudible murmur. "When did I stop being enough for you?"

The truth, Will knew, would shatter everything, would send everything past the point of no return. But if he lied, Jem would know, the way Jem always knew.

"Almost four months."

Jem flinched involuntarily, as if he'd been struck. Will could see his mental calendar flipping back, until-

"Oh, Will... you didn't..."

Will looked down. "I... I don't know what came over me. I guess I'd been thinking about her, and... and I was so worried about you, being in the hospital..."

"Perfect opportunity, I suppose." Jem's voice had lost its passion and was now dull. Lifeless. So different from his usual affectionate, steady voice that Will felt his own tears spill over. "Didn't I tell you at the beginning of all of this, Will, that I was very sick and frail and dying and would never be otherwise? I told you then, that if you wanted someone else, someone that could have given you more than I had to offer, you needed to leave now so I didn't fall deeper in love with you if you were just going to break my heart later? I gave you an out, Will, and you stayed." Jem had tears falling freely now, but they did nothing to detract from the power behind his words. "Why did you stay, if my love was not enough for you? If I was not what you wanted?"

His voice wavered as he looked at Will for an answer.

"Jem, I... For once, I just wanted to love someone that I knew would be there in a year, two years, five years. Even if I only loved them for a week. I wanted love without illness constantly lurking in the corner, and without Death threatening to steal my love away. That doesn't mean I regret us," Will said soothingly, reaching out to lay a hand on Jem's arm.

He jerked away from the touch as if it burned him. "Don't," he whispered. "Please."

"Honey..."

"No." It was a broken whisper, carried over the Thames and up to the newly twinkling stars. "No more. I'm done."

"You aren't saying..."

"Will, you knew this would happen from the moment you slept with Tessa. I still love you, but you've made it clear you have someone else in mind."

Jem inhaled shakily and looked away from Will. "As much as I'm breaking my own heart, we're through."

Cold reality settled in Will's gut as Jem turned and trudged back towards their apartment. "I'll be gone by morning," Jem said softly. "And I'll leave my key."

Will stared over the river for an eternity, giving Jem time to get home without his presence, then traced his ex-lover's steps back home.

~•~•~•~•~•~•~•~•~•~•~•~•~•~•~

Jem quietly packed up his things into a small suitcase and his violin. His assorted medicine bottles- for everything from pre-bronchioloalveolar carcinoma to post-traumatic stress disorder- glared accusingly at him as he zips the bag shut, dropping it by the door. Worn out from crying and the cold, Jem dropped exhaustedly onto their- Will's, he is trying not to think of this place as his anymore to make leaving easier, but it is so hard- couch and fell asleep within minutes.

Will, separated by just a hallway and a closed door, stayed awake until he heard Jem's breathing level off out of sheer habit, then fell into the cold embrace of sleep.

But sleeping was not restful for either, and dawn broke to find fresh tears on both faces.

~•~•~•~•~•~•~•~•~•~•~•~•~•~•~

When Will woke up, the apartment felt empty. He knew, without getting up to check, that Jem already left. Standing and stretching, he walked out to their living room to see something out of place on the coffee table.

A folded note, a small black box, and Will's phone with the earbuds plugged in to it. Sitting down, he put in the earbuds and clicked his phone on.

His heart gave a little lurch at the picture of the two of them at the park shone up at him. It had been an unusually good day health-wise for Jem, so Will had insisted they celebrate at the park with a picnic. Jem, amused and forever patient, had agreed. At the end of the day, Will had taken this picture. (And by that he meant paid a guy two dollars to get it without Jem noticing.)

Will was on his back on the blanket, with one arm under his head lazily and the other around Jem. The other boy was laying with his head on Will's chest, slender frame tucked close to Will's side. Both were smiling, and Jem's eyes had sparkled a lovely silver in the slanted evening light.

Shaking off the memory, he swiped right and mindlessly entered his password- Jem's birthday, of course it was- and peered at the screen.

It was open to music, a playlist Will had never made himself or seen before. It was simply called "Listen" and consisted of only two songs. Laying back on the couch with his eyes closed, Will hit 'play'.

All of this time, I still can't believe... I carried you on my shoulder as we grew older. The symphony we had together reached the farthest. Love captured perfect moments, till you became a solo artist...

The soft violin in the background of this song was exquisitely painful.

Now I won't hurt to hear you crying, whoa (who-oa). 'Cause I know how you played my heartstrings over and over again...

Will lost himself in the song and the emotions and the memories and curse James Carstairs for leaving him this song that fit Jem so freaking well it hurt.

I'm done with all the lies, I'm done with all the pain, I'm done with all the time wasted loving you, and I can't take it no more, take it no more. I'm done with the screaming, I'm done with all those silly love songs that keep on playing...

Will wasn't sure if Jem meant this as a message or as a torture of the most deep and personal kind. All Will could see, even with closed eyes, was the betrayal on Jem's face. The song played on, minutes that felt like hours until the artist delivered the final line.

Go ahead and play me your sad songs. (Can you hear the violin?)

Can you hear the violin?

Will could always, always hear Jem's music, even now. This song was his. Forget whoever the artist was- Jem could've written this song for how much Will's heart ached.

The opening chord of the second and last song began, and Will squeezed his eyes shut to stop the tears.

Forgive me, I may have said things that aren't exactly the way that I feel... I told you I'd be strong, I said that I'd moved on. But it doesn't take long to realize...

Will's stomach tightened slightly. Was this the part where everything fell back into place, or where he realized how badly he'd messed up? What was Jem saying with these songs? What did Will want him to be saying?

That I'm not over you...

"I'm not over James Carstairs." It rang in the apartment, making Will sick with its implications.

But if there is somebody that makes you feel happy, tends to your heart in the ways I'd been lacking, then who am I, who am I to stand in your way...

God, had he really thrown away Jem for Tessa? Yes, it might be nice to have a love he could kiss with zero fear of judgment in public from the close-minded, or have a love he could truly plan for the future with without a dark shadow over their heads, but was that worth throwing away the love and dedication Jem had given him?

No.

And now Jem was out there, alone in the world, thinking he had somehow failed Will.

Will was so disgusted with himself he missed the next phrase or two, then resumed listening.

Do what you have to, 'cause I'd never blame you for not choosing me.

'But I'll blame myself,' he thought. 'Oh, God, Jem, if something happens to you...'

The way that I feel is no longer your burden.

What had Will been thinking? Tessa was not his Jem. Not his angel. Not his angel who had no one else in the world, a horrible sickness, and now a broken heart on top of it all. Jem was not a burden- Jem was a gift, and Will had been blessed with him for four wonderful years as lovers. Even longer as friends.

If there is someone that can make you feel perfect, then who am I, who am I to stand in your way?

For once, William Herondale had no words.

The song came to an end, and Will unfolded the note with shaking hands. It was very short, and the neat script had an undeniable tremor to it, as if Jem had still been crying or, at the very least, his hands had been shaking as badly as Will's own.

William,

I truly am sorry I did not note your unhappiness earlier. For my own sake, I wish I had not found out the way I did, as that led me to be perhaps harsher than I meant to be. That's why I left the songs- you know I was never good with words. That was always you. But music has always been my safe place, and I use it now to try and show you exactly how I feel.

The little box is for you. I had actually planned on giving it to you last night, before I discovered the truth. I wish you all the luck in the world, and I pray to God it won't always hurt this much to miss you.

You were my first love, and you will be my last, I am sure. I love you still, even though I tell myself you are no longer mine to love. I hope part of you still loves me.

- James C.

Will exhaled slowly and opened the box. Inside, there was a silver band with a face of blue gemstone so deep-set that they appeared to run together, giving the ring a smooth and continuous surface.

Silver and blue. Together.

One side of the band had the castle insignia of the Carstairs family crest, the other the heron in flight from the Herondale's.

Simple, elegant, and beautiful. This was clearly a custom-made ring Jem had designed.

Jem had been planning to propose, and what had Will done? Thrown everything away.

Will collapsed back onto the couch cushions, feeling drained. Putting the earbuds back in, he slipped the ring on to the fourth finger of his left hand and hit 'repeat', listening to Jem's goodbye songs over and over again.

A/N: Well. That happened. Anyway, the two songs are "Violin" by Jason Chen and "Who Am I" by Chester See. Listen to them in their entirety for maximum feels!