The Clockwork Express (horror or suspense?)

One of my dream I wished to share. Here it is: The Clockwork Express It’s called the Clockwork Express. This experimental train can travel long distances faster than any train, thanks to its complex gears mechanism which is where it got its name. These gears travel through the whole train and some are even visible from the outside as a design decision. Today is the official inaugurative run of the train. I was chosen to participate for the first ride with a group of 20 people and write a review about the experience. After boarding, I sit in my cabin with three passengers. There is a woman and two men, dressed in professional outfits. The woman is carrying and notepad and is already taking notes. We wait silently for the departure. A few minutes later, we hear the engine start and strange vibrations begin to run through the cabin. The woman reminds us that the vibrations are caused by the gears system below our feet then, the train departs. The woman looks at me and ask: - ”Did you know about the little girl who died on this train a few days before the inauguration?” I tell her that I haven’t heard of that and continue by saying that if it was true, they probably would have canceled today’s ride. Anyway, she continues telling the story of what happened to the little girl. “Before yesterday, the daughter of the man who designed the gears mechanism was playing around on the train. That day, there was an important maintenance of the machinery and some panels on the floor were removed. The investigators think that the girl managed to get past the attention of the engineers and hid under the floor, exploring the maze of gears and cogs. When they started the engine, nobody noticed the child getting crushed under the pressure of the powerful contraption. They say the corpse was removed and that she received a proper burial. But rumors say that the sheer complexity of this metallic monstrosity persuaded the authorities to leave the body in there.” A chill goes down my spine. “There’s no way they would leave her remains inside the train, right?” Suddenly, the smooth vibrations in the cabin become louder. The floor starts shaking violently. I can only imagine that something is blocking the gears somewhere under our cabin. The vehicle quickly stops to check what is going on. Everyone stays silent during the inspection of the engineer aboard and I’m trying my best to forget the awful story the woman just told me. I successfully calm down and close my eyes, taking deep breaths. My serenity immediately vanished when I heard three knocks right under my feet. “That’s nothing! Just my imagination.” Again with the knocks, shifting into desperate scratchings. And then, no more sounds for a couple of horrifying seconds. Soon after, a muffled voice from below implores: - “Please… Let me out…” followed by a faint cough. I jump from my seat. The terror filled my whole person as I run away screaming: - “I want to get out! Please, let me out!” I dive out of the still stationary train. I run some distance from it and watch it resume its run. Was that the last chance of survival for the little girl I just ripped away from her? Or a revenant haunting the passengers? Whichever it is, I am truly sorry. You didn’t deserve that.