They had, they knew, very slight chance of being exchanged so long as the war lasted.

A few general officers, or others whose families possessed great influence, were occasionally exchanged; but it was evidently the policy of Austria to retain all prisoners.

In the first place she desired to reduce Frederick's fighting force, and in the second, the number of Austrians taken had been very much larger than that of the Prussians captured, and the support of some fifteen or twenty thousand prisoners of war added to the drain on Frederick's resources.

Three campaigns had passed without materially altering the position of the combatants, and as many more might elapse before the war came to an end.

Indeed, there was no saying how long it might last, and the prospect was so unpleasant that the two officers were inclined to run a very considerable risk in attempting to obtain freedom.
A week later the snow began to fall heavily, and the moat froze.
"There is no getting across that without being seen, even on the darkest night," Fergus said, as he walked up and down the rampart with his two companions, "unless the sentry was sound asleep; and in such weather as this, that is the last thing likely to happen.
Unless something altogether unexpected occurs, we shall have to postpone action till spring comes.
"Now that we have bought some books we can pass the time away comfortably.