Disclaimer: I do not own any of the characters from The Mortal Instruments nor am I associated with anyone who does. Enjoy the story!
Magnus began to panick as he searched for his boyfriend. He ran throughout the Institute, covering his nose and mouth with his sleeve so he wouldn't breathe in the fumes. Somehow, Sebastian had gotten into the Institute and started a fire. Everyone was safe outside, but Magnus realized Alec was still inside and went to look for him. He heard a noise and stopped. He heard it again and recognized it as banging. Someone was banging on the door. He ran towards the noise and stood in front of the door. It was see through, and Alec stood on the other side, panicking and shouting for Magnus to open the door. Magnus shook the door handle, but it was locked. He tired to use magic but it wouldn't open. Dark magic, he thought as he looked back at Alec with sad eyes. Alec continued to bang on the door and Magnus put his hands against it. He vision began to blur as his eyes filled with tears. Alec pressed his hands on the doors so that their fingers lined up.
"I love you, Magnus." He said. He was crying as well too, knowing he wasn't going to be winning this fight.
"I love you too, Alec." Magnus wanted to scream at him to not give up and to try to breathe, but Alec's eyes were already beginning to droop. Soon, Alec was sliding to the floor in a coughing spasm and eventually fell silent. Magnus slid to the floor as well, and looked at his boyfriend, now dead, and began to sob. He thought about how beautiful this morning had been. He woke up to Alec's big blue eyes staring into his. He gave him a "Good Morning" kiss and made breakfast for them both. After that, they blasted out their favorite sons and danced together. He wished that moment could last forever. He deciced he would never let go of that memory. And he would never let go of Alec, no matter what happened.