The watchman's horn--tute-horn--sounded at the bridge and the squad responded through their commander; whistles also shrilled, being police signals.

The student was perceived.

It was a critical moment.

The next moment he would be challenged, and at the next, have a carbine or sabre levelled at his breast.

He retired up the alley, precipitately, wondering where the persons whom he befriended had disappeared so quickly.
A very faint light gleamed from deeply within, at the end of a crooked passage through a lantern-like projection at a corner.