PARKLAND — She was afraid of what it would feel like, but she needed to know, so Melissa Falkowski pulled into the faculty parking lot. She took a deep breath in through her nose and climbed out of her car. She was back, in front of Marjory Stoneman Douglas High School.It had been a week and a day since the language-arts teacher had hidden with her students in her classroom closet while a gunman killed 17 people with an AR-15 rifle. Melissa, 35, had often said that she spent more time in her classroom than at her own house; that Douglas, where she had taught for 14 years, was home. Now, as she walked toward the entrance, she wondered if she knew where she was at all.In the past eight days, she had lost 10 pounds. When the bedroom light ticked off, she stared at the ceiling. She took calls from Anderson Cooper, Jake Tapper, the Today show and Good Morning America. "You try to do the best you can for the kids you are supposed to keep safe," she told them.As a journalism teacher, Melissa wanted to answer their questions, and keeping busy kept her calm. But when the microphones were unhooked from the collars of her Douglas T-shirts, she found herself thinking back to that day in her classroom. Driving her 9-month-old daughter to day care, Melissa couldn’t stop sobbing."What if I’m not safe?" her son asked the day after the shooting, when she woke him up for school. He is in the first grade at the elementary school down the street from Douglas, and her husband didn’t want to send him. But Melissa knew they needed to do anything they could to feel normal. She kissed her boy and told him that his teachers would take care of him.And that’s what she was trying to do now, walking up the concrete steps to the second-floor hallway that housed her classroom. She didn’t know what it would feel like to be in there, and she didn’t know if she’d be able to step into the supply closet where she and her students had tried so hard, for nearly two hours, to not make a sound.But her students were coming back, some as soon as Sunday to get their things, and Melissa needed to make sure that she would be okay in there, for them. So she turned her key in the lock and opened the door.* * *Before it became the day that changed Douglas forever, it was Valentine’s Day.Melissa woke up before 4 a.m. to look for candy hearts for a poetry lesson. After striking out, and getting a workout in, she came home to a gift from her son: "World’s Best Mom," said the red mug, covered in hearts. Students bearing carnations fluttered in and out of classrooms while Melissa’s students read love sonnets. During second period, a fire drill stole 20 minutes of class time. Otherwise, it was a normal day.When the fire alarm went off again, Melissa and her students were annoyed. Two drills in one day was a rare, but not unheard-of, nuisance. She wondered if someone in the culinary class had burned something. "Okay, you know what to do," she told her students over the bleats of the alarm. "Line up!"As they pushed through the double-doors at the end of the hallway and shuffled slowly down the stairs, a hall monitor told Melissa a kid had set off a firecracker in the 1200 building. Melissa rolled her eyes and, walking toward the stairs, started to relay the firecracker story to two other teachers coming down the hall. And then —"No, no! Code red! Go back!" the hall monitor screamed.Melissa, on the landing above the stairs, yelled down at her students: "Code red! Code red! Come back! Come back!"She ran back to her door, students filing in one after the other. After a long minute, one of her newspaper editors ran in, crying, and Melissa shut the door. They all crouched in the corner. And waited.Just a month earlier, teachers had been trained for an emergency situation. Melissa remembers being told there would be a Code Red, or active shooter, drill, and that it would feel real. This must be it, she thought.The day after the training, she’d taped a piece of paper over part of her classroom door window to create a blind spot in the corner. Hiding there now, with the lights off, she tried to soothe the 17-year-old girl who was crying. Melissa still thought it was a drill. The girl hadn’t yet told her that she’d made it to the bottom of the stairs before she came running back. That she’d heard it, the pop-pop-pop-pop.After a few minutes, Melissa looked at the clock. The high school dismisses at 2:40 p.m., and they never mess with dismissal. The buses that pick up their students have to get to the middle schools after dropping them off. Even when it’s pouring rain, we dismiss, she thought. Melissa pulled out her phone and searched "Marjory Stoneman Douglas High School" on Google. The first thing she saw was "shots fired."Melissa stood up. If they walked across the classroom, the gunman might see them. Too many windows. Too much exposure. But she had to get her kids into the storage closet.It’s as long as a parking spot but half as wide, and Melissa moved quickly to pull her media cart out of it before running back to her students. "I need you to go quietly," she whispered, "a few of you at a time."After all 19 of them were in there, shoulder to shoulder, Melissa went in, too. She turned off the lights and shut the door. It was dark but for the glare of cell phone screens."What the hell is going on?" the yearbook teacher texted Melissa and two other teachers they are friends with. It was 2:31 p.m. A reply came from Stacey Lippel, an English teacher in the 1200 building: "Shooter up in my floor""Actual or drill?" the yearbook teacher, Sarah Lerner, wrote back."Actual. My door window is blown out""Holy shit! Are you ok???"She said: "Very scared"Melissa texted, "I’m locked down." She texted her husband, "I’m ok and I love you."Standing by the door to the closet, she told her students not to worry. Not to be scared. They would be okay.She hoped it was true, as a text came through from Sarah: One of her yearbook students had been shot twice. From Stacey: She had been nicked by a bullet. She had been yards away from Scott Beigel, saw him trying to close his door.But Melissa put on a calm face, making sure everyone texted their parents every few minutes. Rebecca Schneid, 16, was crying, knowing that she was safe, but that it could change in a millisecond. A newspaper student, Rebecca was always in and out of this closet. Melissa distracted her, joking that they’d have to scrap the next issue of the paper.They stood like this for an hour and a half, cracking the closet door when they got desperate for air. They whispered updates from their phones and tracked down little sisters, somewhere else in Douglas. Robert Schentrup, a student of Melissa’s who graduated last spring, texted to ask if she was okay. He hadn’t heard anything from his sister, Carmen. The girl who’d heard the pops cried into a friend’s T-shirt, trying to muffle the sound of her sobs. They listened to the whine of ambulances outside, the shudder of helicopters overhead.And then there were footsteps.They could hear them, and voices, out in the hallway. Slowly, Melissa closed the closet door. She held her breath as the classroom door opened. They all did."This is the police! Is anyone in there?"She looked at her students but didn’t say a word.Again: "This is the police! Is anyone in there?"She looked at her students again. Then Melissa cracked the door one more time."We’re in here!" she said. "We’re in the closet."They came out slowly, one at a time, hands in the air.* * *She turned the light on.Back inside her classroom on Thursday, everything was as she left it.The desks, blue and yellow and purple and orange, were nested and stacked against the wall. The tables were folded down. She had needed to clear space, that day; after the SWAT team arrived, more than 150 students from other rooms came, and they all sat on the floor, waiting and watching the news unfold on their phones.It wasn’t until Melissa got home that she heard: 17 people. That was when it became very real, when she sat on the plastic rocking chair on her porch and cried for the first time.And that was exactly why she needed to come back now. Melissa was going to have hold it together for her students. So if being in this room was going to undo her, she needed it to happen before they returned.She took a few steps on the linoleum floor, until she was standing in the center of the room. She looked to the right, at her bulletin board. She had posted valentines for her students to take home. Half of them were still there. On her whiteboard was a reminder for a quiz she’d never give.Melissa walked behind her desk. The "World’s Best Mom" mug from her son was sitting where she left it. Her favorite sweatshirt was on the back of her chair. Melissa put her hand on the desk. The room felt so familiar, she said, but strange at the same time.She had wanted to go to all of the funerals, but after Carmen Schentrup’s, she turned to another English teacher and said, "I can’t go to any more. I don’t have the emotional strength." She had been to Jaime Guttenberg’s, whose brother is in Melissa’s fifth-period class. And she’d gone to the funeral of Meadow Pollack, who was in her class last year.When Melissa was pregnant with her daughter, Meadow would ask how she was feeling, and what she could do for her. Melissa can still picture her large, looping handwriting, her name written at the top of her papers.Students officially come back Wednesday, but Melissa had trouble picturing what class would look like. She imagined a scenario in which she’d assign them the next four chapters of Anthem, the book her English III students were reading before the shooting. It just sounded absurd to her, when she said it aloud."I feel like we’re just going to spend weeks hugging these kids and sitting in beanbag chairs and talking, because I don’t know what else we’re going to do," she said. "I don’t know when they’re going to be ready to work on work, and worry about their grades, either. What do I do about grades? I have some kids failing my class, and I feel like I just want to hug them and give them an A."The cart she had pulled out of the closet was still in her computer lab. There were week-old dishes in the sink. All around her were frozen moments: A stack of papers to grade, directions to join Relay for Life on the board, a computer that hadn’t finished shutting down. And then Melissa smiled."You know what I see when I look around?" she asked. "I see the three years I’ve spent in this room, memories with all my students. And I can see that, and I’d rather see that, than two hours of craziness."She walked into the closet. There were half-empty water bottles on the shelf that held copies of Macbeth. Someone had left a size small Vans sweatshirt in the back, on a filing cabinet. Melissa went to the corner and leaned against the wall, the same spot she had stood for 90 minutes. "I feel okay," she said.She knew her students were afraid to come back. One was at the mall the other day when a fire alarm went off ; her first thought was, "Where’s the shooter?" and her second was to run. Another started to panic, left alone for a minute at a gas station.Melissa thought about what she would tell them. She would say, Coming back is an important step in healing. And, This is your school. This is your home. She would say to them, You let him take something from you, when you’re afraid to come home.When they were ready — whether it was Sunday or Wednesday or two weeks later — Melissa would be ready. They could talk if they wanted to talk. They could cry if they wanted to cry.Melissa gathered her purse, her sweatshirt, an old yearbook. The rest she could clean up Sunday, before everyone showed up. She had only wanted to see the classroom. And it looked the same, she thought. She walked out, the classroom door swinging behind her.Then suddenly, Melissa grabbed the knob, just an inch before the door shut. She had forgotten something.She went back and closed the closet door.But inside the closet, she left the light on.Contact Lisa Gartner at [email protected] Follow @lisagartner.