Since I don’t have the exact text in front of me, I’ve written a based on the typical structure and themes of such a case. You can adapt it once you’ve read the specific version. Review: El caso del asesinato en la montaña rusa Rating: ★★★★☆ (4/5)

The story opens on a crowded amusement park. During a thrilling ride on the park’s flagship roller coaster, a scream cuts through the air—not of excitement, but of terror. When the train returns to the station, a rider is found dead, seemingly from a single, precise wound that no one saw being inflicted. The detective must work out how a killer could strike in a moving, enclosed train with every witness facing forward.

It sounds like you’re referring to a story titled (The Case of the Murder on the Roller Coaster), likely part of a mystery series (perhaps Los casos de Enola Holmes , Cinco enigmas para resolver , or a similar collection of short detective stories).

Fans of Murder, She Wrote episodes, Encyclopedia Brown for adults, or anyone who loves locked-room puzzles. If you tell me the author or book series this story comes from, I can tailor the review much more precisely. For example, is it from “10 misterios para resolver antes de montar en la noria” or a specific graded reader (like for Spanish learners)? Let me know!