Just as they made this
alarming discovery, they heard a loud knocking at one of the inner
doors.

'The Swedish prisoners have fled!' shouted Hillner's voice. 'Look out
for treachery!'

'Roller,' said Conrad, 'let Hillner out. He is quite innocent. Why,
it was my step-father and no one else that made the Burgomaster and the
governor suspect him. If any one can help to put a stop to this
business, I am sure it is my old comrade. See, here are the keys all
ready.'

'I will promise you faithfully,' said Hillner from within, 'to place
myself under arrest again the instant the danger is over.'

'In the name of God, then, and may He guide us aright!' said Roller,
opening the door. 'And now, to put all on the hazard of one bold
stroke.'

The three friends immediately set off at a rapid pace for the lower
town. Whatever persons they met on the way, whether men or women, were
pressed into the service, and the little company armed itself as best
it might in the hurry of the moment. The women, for the most part,
could hit on nothing better than to fill their aprons as they went with
stones from the street pavements. The men, with Conrad among them,
threw the light of their torches from both sides at once under the
vaulted arches that spanned the Muenzbach, and were longer or shorter
according as their position required. As soon as it was ascertained
that the way was clear at one point, the little party went on instantly
to the next. Roller and Conrad soon made out, to their great relief,
that the water-tower was still standing. They were by this time
approaching it, and just as they reached the last tunnel, the one
through which the Muenzbach leaves the city, at the point where it flows
away under the street below the water-tower, a youth announced that he
had descried the forms of several men creeping through the darkness of
the archway.

Whilst two of their number went off at once to alarm the garrison of
the water-tower and the men on the neighbouring fortifications, the
rest of the courageous little band took post around the vaulted
entrance of the tunnel, in readiness to give the enemy a warm
reception. This arrangement was not completed without some noise; and,
as a consequence, a head appeared from beneath the archway to see what
was going on outside. It was the head of the treacherous town servant;
and Roller promptly dealt it so severe a blow with a stout cudgel, that
its owner instantly drew back w