At that instant a bell rang.

"There's the bell."

"We must catch her," I cried, and ran though the gate and on to the platform.

But the train was already moving. I tried to catch her, but failed; and a minute later the cars rolled out of sight.

Mr. Aaron Woodward and Chris Holtzmann had escaped me.

What was to be done next?

CHAPTER XXXI

IN THE METROPOLIS

I was thoroughly chagrined when I stood on the platform and saw the train roll away. Now that I had Mr. Harrison and the sergeant of police with me I had fondly hoped to capture the two men, even if it was at the last minute.

But now that chance was gone, and as I turned back to my two companions I felt utterly nonplussed.