They mixed the dirt and dust and floury water all together, and, leaving it for a time to harden slightly, found that the mass held fairly firmly together, and might make a reasonably good plug.
“We must, however, wait for darkness, Roger,” said Harry. “If we put this in after dark it will not be noticed until the morning, by which time it ought to have hardened sufficiently to prevent its being pushed out again. If we were to do it now, it would be noticed when our friend the spy comes round for a final look at us, and would doubtless be removed again before it had had a chance of setting.”
Darkness soon fell, and then the two silently and carefully pushed in the already nearly solid plug of earth. They had sufficient to fill the little opening completely, for they heard some of it patter down on to the stone floor outside.
“There,” said Harry, when they had finished, “if they do not find that before morning, it should be hard, and then I doubt whether they will trouble to bore it out again after it has set; but we shall see.”
It was now perfectly dark in the cell, for even on the most brilliant moonlight nights the light could not reach the cell, because of the high walls all round the quadrangle outside, which prevented the rays from streaming in.
Being exceedingly tired, and rather sleepy, the two friends spread their jerkins on the block of stone forming the table, as it was far too damp to lie on the floor, and were soon fast asleep in one another’s arms.
They were awakened the next morning by the sound of the trap shutting after the morning’s supply of food had been put in; and their first thought, before even glancing at the meal, was to see if the plug had been disturbed. To their great joy, so far as they could tell, it had not been touched; and, upon testing it, it proved to be perfectly hard and quite immovable.
“It will take them a little time to get that out, even if they try to do so,” said Roger; “but I trust that they will not attempt it. If they do not, we are at least safe from observation, if not from being overheard. But, to be on the safe side, I think it would be wisdom on our part to converse only in whispers.”
“I quite agree with you there,” replied Harry; “one never knows who may be listening. And now let us turn our attention to breakfast, and see whether we have anything different this morning from that miserable and tasteless meal porridge and black bread.”
They examined the food and found that, this time, instead of the porridge, a bunch of bananas had been provided; but, for the rest, the black bread and water were there as before, and nothing beside.