It had been two years since El disappeared in a cloud of ash, dragging the demogorgon out of this world. It had been a year since Nancy and Jonathan managed to get the lab shut down for good, it's doors shuttered and chained. El had not found her way back from Upside-Down, and Mike knew he had to find a way to go and get her. The girl he loved was stuck and he wouldn't rest until she was home. If there was any place that could help him figure out how to get to her, it was the lab where she was raised.
When it had finally happened, the lab was shut down in a hurry. Anything expensive, irreplaceable, or of use somewhere else was loaded onto trucks over the course of just a few days. Everything else - desks, chairs, file cabinets and the like - were left behind. As he walked through the woods on the way to the perimeter fence, Mike hoped that the files related to Brenner's experiments were included in the inventory left behind.
He was pleased to find the fence-line was already showing signs of failure, as several large gaps had been dug underneath by the local wildlife. Shoving his backpack through ahead of himself, Mike crawled through the gap, gouging a deep scratch into his arm on the bottom of the chain-link. Brushing off the dust, he made his way to the most obvious entry he could think of: the front doors. After making quick work of the padlock with a pair of bolt-cutters hidden away in his pack, he pulled the chain free of the plywood panels and let himself in. He pulled the doors shut behind him as best he could, hoping it wouldn't raise the suspicions of any security detail that might drive by while he was searching.
Retrieving a flashlight from his bag, Mike slung the pack over his shoulders once more. He winced as the strap rubbed the scrape on his arm, and he realized he would have a hard time explaining the blood on his sleeve when his mom went to wash his shirt. "That's a problem for later," he thought, as he began to explore the dark and dusty corridors of the lab. It didn't take long to find the main stairwell, and he decided he would go to the bottom and work his way back up. As he wound his way down, he had to fight the urge to turn back. With no electricity or equipment running, the silence was unnerving and every footstep echoed away down deserted halls and returned like unearthly moans. He steeled his nerve, knowing that however much this place scared him, the place she was stuck was infinitely worse.
Soon enough, he found himself in the lowest level, in a large open room. He recognized it immediately from Hopper's descriptions and Eleven's pained explanations. This was where they made her send her mind out into the beyond to find people and monsters. Along the far wall, the plaster and tiles still bore the scars of gate, now closed and silent. In the middle of the room stood a large tank with a sliding metal shutter. The Bath, she had called it. She had explained all about the tank and its purpose on the drive to the school that terrible night. Looking at it, he knew immediately it was a name Brenner had carefully selected to minimize her fear. Mike couldn't even begin to image how terrifying it must have been to be lowered into the deep water, the top sealed up and the shutter slammed shut, cutting out the world. He took a step forward, inspecting the cylinder, now standing empty and dry. A single, large crack ran up the bottom half of the glass like a jagged scar.
Knowing there was still a lot of lab to explore, Mike continued searching the basement for anything that might help him in his quest. Finding nothing, he climbed back up one floor and tried again. This level contained quite a few of the old lab spaces and offices. The experiments were long gone, the spaces now filled with stacks of chairs, desks, office equipment and file cabinets. Sliding open several drawers, he satisfied himself the contents had been removed before relocating the cabinets. Returning to the main floor, he found things much the same, though more of the offices sat empty, their furniture having been consolidated downstairs.
As he turned a corner down yet another hallway, the walls changed from dark-wood panelling to sterile white tile. He came to a pair of security doors, now sitting propped open, their handles chained to bolts mounted on the walls. His heart beat faster. "This could be what I'm looking for," he thought. The rooms along this new hallway looked like they were set up for observation, rather than typical lab work. After passing several empty rooms, he came to one with stack after stack of file boxes. Playing the beam of the flashlight over the ends of the boxes, he found they were cryptically labeled with project names and date ranges; going through them all would not be an easy task.
Knowing he needed a better idea of just how much there was to search through, he checked the next room. It too was stacked full of boxes, hopefully detailing every aspect of the work the lab had been doing and giving him answers as to how to find her and bring her safely home. The next room lacked any windows so he was unprepared for what awaited him on the other side as he swung the door open. The workers in the lab - those who were even allowed down this wing - had usually referred to it as 'the bedroom.' After the events of 1983, no one had wanted anything to do with the old project, so they had simply closed the door on the room and pretended it didn't exist.
Mike's heart froze as he stepped through the door and surveyed the small space, knowing immediately what he was looking at. He panned his light around the room, taking in the contents. A plain metal desk and chair. A small shelf with a few towels. A small bed. Lying on the floor was an old crayon drawing, the tape that once held it to the wall having long ago lost it's hold. It was a simple drawing of a little stick figure child and a taller stick figure man. The figures were carefully labeled "11" and "Papa" in a child's handwriting. Without warning the tears stinging at the corners of his eyes broke free. This had been her room; her prison. This had been the room where Eleven sat in isolated silence, waiting for Brenner to appear and exploit her powers.
Mike slipped the picture in his bag; something of hers to hold tight to. Aside from memories, this drawing was the only thing he had that proved she had been a real girl who existed and lived and breathed. He looked around the room, desperate for more signs of her to cling to, his resolve beginning to dissolve into hopeless despair. Sitting in the middle of her bed was a little stuffed lion. He sat on the bed and picked up the stuffed animal, gently brushing off the dust that had collected in the two years since she had held it. In spite of the time separating them, Mike could almost feel her presence as he looked around the room. His heart broke once more as he imagined the timid existence she lived. There were no signs of other toys or games in the room, nor crayons or paper. That meant even her simple drawing had been a rare treat, probably a reward for completing one of Brenner's terrible tasks. Almost nothing existed that would betray the knowledge that a little girl had grown up in this tiny space. Just a little desk and a little shelf, a little bed and a little stuffed lion.
Anger and sadness swirled through his mind, fighting for control as he sat there hugging the lion tightly to his chest. Tears fell anew, running down his cheeks unheeded as he contemplated the loss. She had lost her childhood in this cold and lonely place. She was lost in the Upside-Down with no way to get home. He had lost the girl he loved. He had realized shortly after she was gone, that he had fallen in love with her at first sight, that night in the rain. He felt his soul was bound to hers in some way that he couldn't put into words and he felt like a huge part of his was missing with her gone. He had never gotten the chance to tell her how he felt, beyond his rambling attempt in the cafeteria and one brief kiss. It had been clumsy and awkward but it had also brought a smile to her beautiful face and that was the memory that burned bright in his heart whenever the despair tried to force its way in.
As the tears ran silently down his face, he lay down, barely fitting in the tiny bed where she had once slept. He pulled the lion tighter to his chest, closing his eyes.
"I'm sorry El." he whispered into the darkness. "I'm so sorry. I don't know how to find you, but I will find you. I love you Eleven."
Somewhere in the tears and the grief, Mike drifted off to sleep, his head resting where her's once lay. Hours later, that's right where the Military Police officers found him. They had been going around the building on a routine patrol and had easily spotted the cut lock and the chain lying in a heap by the door. They woke him and escorted him to their truck waiting outside. Clinging tight to the lion, refusing to let the connection with her fade away, he managed to convince the MPs he had run away from home, knowing he could find shelter at the lab.
He had walked shamefully to his front door with an officer on either side. He had stood there, head hung low as they explained where they had found Mike and detailed the numerous federal laws he had violated by breaking into the lab. At one point, his mother had caught his eye and given him a knowing look. She didn't know the full story, but she had pieced together a lot of what had happened between Mike and the mysterious basement girl and knew it had ties to the lab.
"We're not pressing charges this time," one of the officers explained. "Just give us your word you're not going back there."
"I promise. I won't go back there," Mike assured them. At that, they turned and headed back to their truck.
Walking into the house, Mike made a promise to himself as well; the next time he went to the lab, he would have to be much more careful about covering his tracks.