The Day the Dead Came to Show and Tell by Mira Grant

music playing to cover the sound of the alarm, when someone knocked on their door. Ms. Teeter, who had been sitting ramrod-straight at her desk with her gun hidden in her lap, got laboriously to her feet and walked toward the door. It wasn’t locked. The damn locks had failed to deploy. She’d been part of the committee arguing against taking the ability to manually lock the doors away from the teachers. The bureaucrats who said that it was for their own safety had never been put into a position like this one, of that she was sure.
    She was just glad she’d had the presence of mind to close the shades after the windows locked. The sound of the steel plating dropping to block any chance of escape had been loud enough to attract some attention from her students, but they hadn’t seen the glass go blank, or realized—yet—that there was no way out of the school. Once that happened, the tears would begin. She wanted to avoid that for as long as possible.
    The knock came again. A few of the children had looked up toward the sound, interested but not alarmed. She had worked very hard to keep them calm, and the last thing she needed was for some panicky little twit to come charging in and upset everything.
    At the same time, she had been a kindergarten teacher for long enough that she was running up against mandatory retirement age, and one doesn’t spend that much time with small children without retaining at least a sliver of softness in the heart. “Who is it?” she called. Zombies didn’t knock, and whoever it was, they weren’t pounding; she had the time to be polite.
    â€œElaine Oldenburg! First grade!”
    There was a note of panic in the younger teacher’s voice that she didn’t like; no, she didn’t like it at all. Panic had a tendency to spread, especially when it was offered to the younger children as an option. “I’m sorry, Miss Oldenburg, but we’re in the middle of class right now.”
    â€œPlease, let us in.”
    Ms. Teeter’s eyes widened slightly behind the lenses of her spectacles. Was the woman roaming the halls with her entire first-grade class? Didn’t she understand the situation? “Go back to your own classroom,” she suggested, trying to keep her voice from shaking. “I think you’ll find that to be a much more comfortable arrangement.”
    â€œWe can’t,” hissed Miss Oldenburg, dropping her voice so low that Ms. Teeter had to strain to hear it. “There are…problems…between here and my classroom. Let us in , unless you’d rather have fifteen students on your conscience.”
    Miss Oldenburg clearly knew something she did not. Ms. Teeter spared a glance for her own nineteen charges, most of whom were still sitting and coloring quietly. A few had put down their crayons and were watching her to see how she would answer this stranger’s request. None of them seemed frightened. She was direly afraid that that was about to change.
    â€œI’m opening the door,” she said quietly, and turned the knob, pulling it inward to reveal a red-haired woman wearing a Kevlar jacket over a flowered dress. She looked too young to be in charge of anything, much less an entire class of first graders, but they clustered around her like she was the only port left in a storm. Ms. Teeter looked at Miss Oldenburg solemnly, scanning her for blood or signs of injury. Miss Oldenburg looked back, just as solemnly, and didn’t say anything.
    Finally, with a sigh, Ms. Teeter stepped to the side. “Please don’t make me regret this,” she said. “The children don’t know what’s happening.”
    â€œNeither do my children, not really,” said Miss Oldenburg. She let go of the little girl whose hand she had been holding and shooed her inside. The rest of the class quickly followed, some of them even heading for the shelves where the picture books and quiet toys were