Night trains are disappearing across Europe, but a Berlin start‑up is working on compact and comfortable sleeper cabins. Their aim is to create an affordable alternative to short‑haul flights. The concept relies on space‑saving modules that can accommodate almost twice as many passengers – which the company says could bring ticket prices down to the level of air travel while producing far lower emissions. The cabins are still prototypes, but the founders are determined to revive sleeper trains