"We'll all swing for it, an we bide here parleying much longer," began Rob desperately.
He broke off abruptly, for even as he spoke, a window in the wall opposite was flung open, and a man's face peered out into the alley.
Instinctively the three drew back into the shadow. But it was too late. The disturbed burgess had seen the three figures, and in an instant he suspected the truth of the situation.
With an exclamation his head disappeared from view, and a moment later they heard the bolts of a door round the corner of the building shot back and the man rushed into the street shouting:
"The prisoners are escaping! Look to your prisoners."
Captain Protheroe seized Barbara's hand, and they began to run rapidly down the alley. They heard the sentinels running up the street and shouting. They darted round the corner as their pursuers turned into the alley.
Rob had disappeared.
The alley led into a wider street, parallel to that in which the sentries had been posted, at the main entrance to the shed. Down this the fugitives turned, but were met by a knot of men running towards the shouts. Captain Protheroe tightened his grip on Barbara's hand, desperately, and ran straight towards them, waving his free arm in the direction of the prison.
"The prisoners!" he shouted. "They are escaping, look to them."
The ruse succeeded. The men hesitated a moment, staring doubtfully at his uniform, and then proceeded at a run towards the prison, shouting confusedly. On they ran right into the arms of the sentries, who at that moment turned out of the alley.