The Shadow gives a slow shake of his head. "I made that mistake once. I'm never retiring again." He refrains from alluding to the alternative, this time. That the job will someday kill him seems inevitable, and yet he's made it this long.
The mountains are already a bumpy blue line, the contours beginning to show on the horizon, but they still have a while to get there. He'd forgive her if she dozes off in her seat. The last comment has left him in a contemplative mood.