Martha made sure I stood right beside her during the after-midnight shift. While my hands performed my simple task, I stole glances at her. After about half an hour of sorting chocolates in silence, she looked at me with clear blue eyes. "It's Katharina's ghost who's troubling you."

I frowned, not sure what I should do with this bit of esoteric information. I didn't believe in ghosts. Martha turned back to the conveyor belt and nodded slowly. "I can't blame you for not believing. But if you're ready to listen, I'll tell you more about our factory spectre."

We had another three hours of shift ahead, and I wouldn't go anywhere, so I nodded, doubtful I really wanted to hear Martha's story. She picked up the thread in her brittle voice. "Katharina was a single factory worker's sole daughter. Her mother brought her into the production hall at an early age."

An overseer passed by, and Martha interrupted herself. She continued once he left. "Way back, few working-class children attended school, at best a rare lucky boy. Child employees started at eight or ten years of age. Katharina was the youngest by far. She'd spent her time in the factory since she was a toddler. The poor girl never knew another life, running little errands as soon as she could walk, doing simple jobs later."

Martha was a gifted storyteller. I imagined young Katharina skipping through the halls, ponytail flying and a smile on rosy lips. According to Martha, she got a place on the line at the age of five and supervised the conches at seven. Because she grew up in the factory, little Katharina possessed an extraordinary sense for chocolate quality. Her mother must have been proud, aware her daughter would one day become overseer or even a member of quality management.
Martha interrupted her tale with a sigh.

"What's wrong?"

"Nothing, my dear, it's just memories. One sunny spring afternoon, a butterfly found its way into the meticulously clean production area. Young Katharina hadn't seen a lot of wildlife, spending six days a week in the factory and living with her mother in the single workers' dormitory around the corner. Fascinated, she followed the colourful insect, mesmerised and forgetting her tasks. She observed the butterfly landing on the chocolate mass in a conche. Maybe it was lured by the sweet scent, maybe just disoriented or tired. It took Katharina a while to understand the tiny animal was stuck and fought for survival. While it struggled, it sunk deeper into the chocolate swamp, in danger of being crushed by the roller. Katharina couldn't let this happen. She climbed onto the giant conche and leaned over the rim, stretching further to save the butterfly."

Captivated by Martha's story, I let a faulty chocolate slip by. The old woman was quick to correct my mistake. Ashamed, I turned back to my station, determined to concentrate on my task. However, after a while, I couldn't resist the temptation to ask. "And did she save the butterfly?"

Martha took her time to answer. Her face seemed even more wrinkled than usual and her eyes watery. "Aye, she did. But they had to stop conching to retrieve Katharina's tiny body, wedged between the rollers. When they freed her and laid her on the cold factory floor, a beautiful butterfly rested for a moment on her forehead, before it took off and left the hall through a roof window. No butterfly ever visited the factory after this incident. Conches were later fitted with lids, nonetheless."

Now, tears rose in my eyes, too. I sniffed, glad for the compulsory protection mask to hide how much the story upset me. Martha never looked at me while she spoke about Katharina's burial. In my mind, I followed the sad procession of factory workers and observed the small coffin being set to rest in the community cemetery.

Martha finished her story in a hushed voice. "Katharina's soul never found rest. Up to this day, she haunts the factory halls, testing the texture and temperature of the chocolate and surveying the conches as she used to when alive. Only a few people have the special gift to perceive her walking by and feel the touch of her chilly hands. Katharina's ghost isn't malicious, just a child craving attention, playing pranks."

Yes, I thought, wondering if the ghost still searched for butterflies and eternally longed to explore the world beyond factory walls, the world young Katharina never got to know.