"We're still doin' the right thing, technically? But from what I heard the ministry doesn't take too well to decommissioned craft roamin' around and uh..."

He gestures around

"Some of us'd be dead without it. I ain't so much worried about me. I did my whole life an' messed it all up. But there are a bunch of kids here that need this train an' I wouldn't feel right without given 'em every last scrap of time I could buy 'em."

It's a matter of karma and being even remotely a decent person.