My Patients Are All SSS Fiends - Episode 4

The protagonist's battery is low, and their dark magic is malfunctioning, drawing suspicion from a fellow passenger named Lucien. While investigating the carriages, they discover a 'Record of Evil Spirits' Diseases' and learn they must earn 'points' to speak and survive. They also unlock a system that rewards medical skills, having already treated an 'SSS-level' entity. Two newcomers, Ruth and Jack, approach the protagonist, revealing everyone is trapped in a deadly 'Death Train' dungeon and hailing the protagonist as a legendary player who stunned the powerful train conductor.