Nukem and the train

You and the guys were in the village, the girls, your group, you decided to go into the forest and found some rails and walking along them, you found a dead-end track and suddenly you realized that the tracks were vibrating as if a train was traveling along them and you saw a train, all rusty and old, driving out of the dead-end track and together you rushed home to your grandparents
The next day you went back to the rails and saw the station, and when you and the guys were climbing around on the nightstand, we found a map of the rails and followed it, and found a strange tunnel, but at the end there was a wall, and then you saw a ventilation shaft and fell into a laboratory for creating a traveling train.
!You are Os!

"Taken from chai"