A/N: I've always wondered what would've happened had Will not been fast enough to protect Tessa from the metal shard explosion at the tea warehouse. Here is what I think would have happened if he hadn't. AU Wessa One-shot (TID – Clockwork Prince).

Disclaimers: First three paragraphs belong to Cassandra Clare, as do the awesome characters! However, sadly, I am not Cassie Clare. Also a few quotes and ideas have been dropped in from other fandoms, like Teen Wolf and TVD. Who doesn't love those?!

"I am Nathaniel Gray!" Tessa shouted up at the metal giant. "And I order you in the name of the Magister to seize this man and hold him!"

Nate whirled on her. "Enough of your games, you stupid little-"

His words were cut off suddenly as the automaton bent and seized him in its pincered grasp. It lifted him up, up, level with its slash of a mouth clicking and whirring inquisitively. Nate began to scream, and kept screaming, witlessly, his arms flailing as Will, finished with whatever he was doing, dropped to the ground in a crouch. He shouted something at Tessa, his blue eyes wide and wild, but she couldn't hear him over her brother's screams. Her heart was slamming against her chest; she felt her hair tumble down, hitting her shoulders with a soft, heavy weight. She was herself again, the shock of what was happening too great for her to hold onto the Change. Nate was still screaming – the thing had him in a terrible pincer grip. Will had begun to run, just as the creature, staring at Tessa, reared up with a roar, and blew apart like an exploding star.

Will POV:

Will had lodged Henry's device into the automaton while it was distracted with Nate. He just hoped with all his heart that it would do what it was created for, and disrupt the clockwork mechanisms. He dropped to the ground, taking cover behind one of the sturdy pillars of the warehouse. Although Henry's intentions were generally harmless, most of his inventions had… undesirable effects.

He glanced up, to check if the others were taking shelter, and saw Jem, half hidden from behind a pillar. He assumed that Charlotte and the rest had seen sense and were doing the same. As he scanned the room, he saw that Tessa was still frozen, staring at Nate in shock. She was herself again, her dark hair curling gently over her shoulders, highlighting the grey in her wide eyes.

He remembered the feeling of running his fingers through the soft strands on the balcony at Benedict's ball, kissing her rosebud mouth. When she had told him she would not break. When he called her his. Will had felt something around his chest loosen, as if there had been a chain constricting his heart, and her smallest touch had freed him. He inhaled sharply; she was so beautiful.

Just then he felt a burst of heat emanating from the automaton – it was definitely going to blow. Will cursed. He shouted frantically at Tessa to get down, to take cover, but she remained frozen. Panic flooded through him. Clearly either she was in too much shock to process his words, or she couldn't hear him over her brother's screaming. Curse Nate,he thought.

In a matter of seconds Will had launched himself off the floor, sprinting towards Tessa. Fear throbbed through his veins; he knew he would never cope if he lost her. He had to reach her. He had to save her.

Finally her grey eyes met his blue ones, and time seemed to slow. She was confused, at first, to see him running toward her, then realization dawned across her face and her rosy pallor faded to white. In what seemed like an eternity, Tessa made a move as if to run, her gaze drifting to the automaton, and back to him. Through shocked eyes, Will saw her relax, as if she thought better of it, and meet his eyes with a steely gaze. His heart lurched in his chest when he saw that the look she gave him wasn't of panic, or even sadness. The expression she wore was of … acceptance. Confused, he looked towards the automaton, and saw that it was glowing, like the final ember rays of the sun before they turned into blackness. His determination propelled him faster as the automaton grew more crimson.

Smiling sadly, Tessa shook her head at him. Her message didn't sink in at first, and when it did, hopelessness struck him to the core, and time seemed to go twice as fast. He wasn't going to make it. He was too late. He refused to accept this though, and ran even faster, though each step seemed to take him further away from her. Tessa's eyes widened, and she shook her head even more frantically. Will knew what she was trying to communicate. It's too late. I will not let you die for me. You need to stay, for Jem.

She truly is Boadicea, Will thought, a warrior soul to the last.

"Go!" Tessa shouted. "Look after -"

Suddenly a blast of flame shot from the mechanical creature as it erupted in all directions. Will threw his arm up, shielding his face from the explosion. Though he had been expecting it, the eruption still left him breathless. He took a hasty step behind the nearest pillar, wincing as a few hot specks of ash landed on his bare hand. A flying metal shard caught Will on the forearm, grazing it with a shallow cut. He braced his body against the pillar, protecting himself from the fire. The explosion seemed to continue endlessly, and Will closed his eyes, her name thrumming through his body with each pound of his heart, each breath he took. He begged silently for her to be okay, that somehow, she had escaped in time, or that some higher being had intervened.

When it was over, and he began to come back into his own, coughing a little as he wafted the smoke away, his first thought was of the grey eyed girl who held the keys to his heart. Tessa.

Tessa's POV

Tessa was frozen with terror for her brother. The shock of everything was too much for her already exhausted body to handle, and she realised she had lost her grip on the Change and had turned back to herself again. She knew that she should be taking cover, for the automaton was glowing a fiery red – it was obvious an explosion was imminent, but she couldn't seem to tear herself away from Nate. She guessed some part of her wanted to save the small part of him that was still human, that was still her brother.

She remembered playing with him in the field near their house when they were only kids. She remembered puling pranks on Aunt Harriet with him. When he bought all the books she desired. When he shared his sweets. Then… then there were the bad memories, like when he poisoned Aunt Harriet and betrayed the entire Institute.

Nevertheless, she was torn over whether to hold on to the possibility of saving her brother or letting the automaton purge the world of the monster inside of him. Nate's screams echoed in her ears as she dwindled. There was a certain melodic sound to them, she thought, as they bounced of the walls and reverberated around the room. She stood, captured, as destruction reigned around her.

Suddenly a voice pierced through her stupor – Will's voice!

Her head snapped towards him and to her surprise, he was racing at top speed towards her. Dozens of questions clouded her mind – when didn't they? – as she stared at him in confusion. Tessa saw his mouth moving, lips forming words, but she couldn't hear him over Nate's screams and the high-pitched whine of the automaton… The automaton! Tessa's gaze shot towards it and saw it glowing, like the first few embers of a fire as it spread. Her blood ran cold. Her first instinct was to run, to get to safety but her head told her that it was too late. She would never make it. If she tried to run, the chances were Will would rush to help her, and then they would both die. No. She would not have him die for her. She relaxed her tense posture, and returned his gaze. It was if they were both in slow motion, him running towards her. She shook her head and smiled at him, saying with her eyes that: It's too late. I accept my choice, but I will not have you die alongside me. You still have time, and people need you to live. Get to safety. To Tessa's surprise and partial anger, he was still running towards her. He refused to give up. Tessa's eyes widened, and she shook her head even more frantically. He had to stay, for Jem if no one else. They needed each other to live!

"Go!" Tessa shouted. "Look after -"

Her words were cut off suddenly after a blast of flame shot from the mechanical creature as it erupted in a wave of fire. The worst part was not the heat. The heat was unpleasant, but not intolerable. Tessa hadn't been as close to the automaton as she had thought. The worst part were the shards of escaping metal flying from the automaton in all directions. She screamed as one hit her, piercing her shirt and sinking to just below her heart. She could feel it as she breathed, grinding under her ribs. One struck her arm, another her shoulder, knocking her backwards. Dozens shot through the air, all striking her with considerable force. The pain was unbearable, like millions of white hot daggers were being plunged into her skin. Blood seeped through her clothes, yet still the explosion continued. She closed her eyes, praying for the pain to end.

Will's POV

Stepping out from behind the scorched pillar, he scanned the room until his gaze fixed on her crumpled form, and he felt as if all the breath had been knocked out of him. He saw now that nothing else existed except him and her. Will took the few remaining steps towards where she lay. He had been so close – if he could've started running earlier – if it wasn't for the curse - But Will stopped those thoughts before he could be drowned in the flow of his own self-blame and bad memories. Tessa was what mattered now. Nothing else. He could only hope…

She lay on her side, folded around herself, looking as beautiful as a china doll. Will hated novels that always compared death to sleep – death was so entirely different – but it was only now that he realized it was true. Tessa looked so peaceful, with her eyes closed and hands nestled to her heart, that she really could've been sleeping, but her burned hands and deathly white pallor spoke otherwise.

Will fell to his knees beside her, and gently pulled her into his lap, cradling her in his arms so that her face was upturned towards him. At this angle he could see the blood that streamed through her clothes, the metal shards protruding from her mid-section. No one could survive that and live.

"Tessa," it was halfway between a sob and a choke. Will's despair was clearly shown in his voice, which was thick with tears. He hugged her close, as if his love alone would be enough to revive her. However, to his surprise, he heard a sharp inhalation, and drew back immediately. He had thought she was already gone.

"Will?" Tessa's voice came to him like a needle of hope piercing through a fog of despair. "Will, is that you?" Her eyes were still closed, and she sounded exhausted. Will was vaguely aware of Jem, Charlotte, Henry and the others surrounding them in a loose circle, looking distraught. They knew it was too late.

"Yes. Yes, it's me," he said softly, stroking her cheek. At the sound of his voice her eyes fluttered open. She looked at him, through him, as if not seeing him at all.

"Will, Will I cannot find you." Her hands were tightly fisted in her clothes, her voice small and panicked, tinged with the American accent he loved so dearly. His heart broke for her.

"I'm here." He said as soothingly as he could. "You're alright." Will felt her relax in his arms as she regained her focus, gazing up at his blue eyes with her grey.

Tessa let out a small laugh. "You always were a terrible liar, Will." Her voice was hoarse, and the fact that she used the past tense made tears begin to prickle behind his eyelids. She'll never know what I've really been hiding, Will thought. He didn't know whether to be sad or relieved.

"How bad is it?" she asked simply, searching his face. Always asking questions, he thought with a sob. Will bit his lip. Jem was usually the best at comforting; Will didn't have a clue what to say.

He was saved from answering when suddenly Tessa gasped in pain, and blood pulsed out heavily from between the shards embedded in her stomach. Her breathing hitched, agony clear in every line of her body as she gripped Will's hand tightly. Will didn't care, just held her closer until her breathing grew steadier.

"Shh, its okay, I'm here. I'm here," Will comforted her, his voice catching slightly at the end. He gently tucked an escaping strand of hair behind her ear and was suddenly taken back to another night, when they seemingly had the entire world at their feet. It seemed like a lifetime ago.

"Do you remember the balcony at Benedict's house?" he asked soothingly, not caring if the others were listening or not. Tessa gazed up at him, her breathing harsh and loud, blood draining from her body without any signs of stopping. Though she did not reply, her eyes showed an understanding. "Well, I want you to know that I have never stopped thinking about that night." A small smile touched Tessa's lips.

"Me neither." She said quietly. Will looked down at her in surprise and smiled back. He had never believed, not for one second, that she might feel the same way as him. He stroked a hand through her curls, and felt a powerful urge to tell her everything, as if he could seal her wounds with words of love.

Seizing the impulse, Will leant down and whispered in her ear: "I love you Tess, and I have loved you, almost since the moment I met you." He heard her a little gasp escape her mouth, but he carried on nonetheless. "I realize that it is unfair to burden this with you now, especially if you do not feel the same way, but I could not go on another second without telling you." Will let out a shaky breath. "I love you, Tessa Gray."

He began to withdraw his head from hers but felt her hand at the nape of his neck, soft and delicate, pulling him back down. Then Tessa said the next six words that would change his entire world.

"I love you too, Will Herondale."

Will sat up, stunned, and looked down at Tessa where she lay in his lap. Her eyes were shining, and she looked up at him with such love and adoration that his heart ached. Then her breathing hitched again, and between one second and the next, her expression of admiration turned to one of utter terror.

A sob escaped her lips, and she whispered so that only he could hear: "I'm scared Will. I don't want to die."

His heart ached for her. Tessa so rarely let anyone inside her mind like that. All of a sudden, Will knew exactly what to do. He bent down and touched his lips to hers softly. The kiss tasted of salt and blood and Tessa.

He drew back slowly. "You'll be okay. You will reunite with your father and mother and aunt, and I'll be with you the whole time."

"You won't let go of me?"

"Never."

She smiled up at him. "Thank you, Will. For everything." He felt the prickle behind his eyelids strengthen, and inclined his head, for if he said anything, he would start sobbing and would never be able to stop.

"Anytime," he said, smiling softly.

Suddenly she began to cough, and there were traces of blood on her lips where there hadn't been before. The smile vanished from his face, like a chalkboard wiped blank. Fear caught at Will's heart, and he grasped Tessa's hand and kissed it lightly, to let her know he was there for her. She had closed her eyes.

"Tessa?" His voice broke.

To his relief she opened her eyes, but they seemed less focused.

"It's okay. It doesn't hurt."

Will's resolve shattered, and a tear escaped down his face as he realized what this meant.

"No." His voice shook, the one word portraying all his feelings he had worked so hard to conceal. No. She couldn't die. No. It was too soon. No.

Tessa nodded weakly, a tear running down her face.

"It's okay."

"Tessa - "

"It's okay" she repeated. "I love you, and -" She took a deep breath. "And I will always love you. You are my first love, Will, and the last love of my heart." She stroked a hand through his hair and traced his lips with her fingers lightly, as if committing them to memory. "Remember that."

Another tear ran down his cheek, and Tessa glanced behind him, presumably at Jem. "If Jem is right, and we do get reborn, then I know we will meet again." Then Tessa smiled, and it seemed to light up the room. "I will see all of you again. This is not goodbye." she said, looking at each of her friends, her family surrounding her. She touched Will's cheek again softly with her hand; he placed his softly over hers, closed his eyes and leaned into their overlapping hands.

"You can let go, Tessa. We'll be with you." The voice startled Will out of his reverie; it was Jem's. Tessa looked at Jem, silently communicating something with her eyes. Will could sense his parabatai's sadness, but there was also… relief at the same time, as if they had solved something between them.

Out loud, Tessa said "Thank you Jem."

Will choked back a flood of tears as her gaze passed to his with a small smile, lingering over his midnight blue eyes, then fixed on the ceiling. He watched as her beautifully unusual grey eyes became less focused, and then closed entirely. He watched as her hand grew slack in his and slipped from his grasp to thud down on the floor. He watched as her chest rose and fell for the last time, and her head grew limp against his arm. He watched as the world lost its colour.

Tears flowed freely down Will's face now as he stared down at the slack face of the girl he would love forever. Time had no meaning as he sat and held Tessa. Slowly, he could hear each member of his adoptive family slip away, leaving them alone. Jem was the last to leave, bending down to whisper something in Tessa's ear, the words like one constant buzzing noise, as if he was listening underwater. One last time, Jem stroked her hair back from her face tenderly. He rested his hand on Will's shoulder and eventually left too.

Will stared down at Tessa's face, as beautiful and delicate as a china doll, and it truly hit him that she… that Tessa was… dead. He had never thought that a fire that burned so fiercely could be snuffed out so easily. But then again, maybe a fire that burned that bright was not meant to last.

With one last gesture, he drew her close, brushed her curls softly behind her face and bent down to kiss her forehead. He lowered her gently to the floor, resting her hands over her heart to cover the worst wounds. Then Will got up and walked away. When he was halfway to the exit, he turned to look at Tessa one last time where she lay, peaceful as if asleep, and choked down one last sob.

"Ave atque vale Tessa Herondale."

A/N: Thanks for reading – I hope you enjoyed it! Feel free to drop a comment, they really mean the world to me! Btw, I am still continuing my other Mortal Instruments fanfic, 'Kidnapped By Her Brother', and hope to update in the next few days. If you haven't read it, then what are you waiting for? Go check it out!