"You wouldn't be alone, is all I mean. Technically my world isn't really advanced, but it used to be at one point." He considered that.

Senku nodded. "It's not that you won't die. You do. At least you experience death, from what I understand. Then you wake up in a suitcase sometime later, a day or so. I asked the train why we come back, and they said the tether makes it very difficult to die permanently. It's new in the sense that most worlds don't have that as a feature, but not new to those of us on the train exactly."