“Here, put this on.” Arty pulled an old trench coat and baseball cap out of his bag.

“Walk with me, pal,” he sneered. “If you make a break for it I’m gunning you down.”

I didn’t need convincing; his narrow-eyed stare terrified me. I stood up and obeyed, even though my panicked mind was running through a list of alternatives – scream for help, or try to grab the gun, if it really was a gun he held in his pocket.