'Here,' came the crisp and half-stifled answer, while the figure of our hero loomed darkly before them, his face muffled in the half of a garment which he had secured from somewhere. 'Come along this wall of the room with me. I realised when they fired that heap of stuff that our position would be untenable, and went to the men who have been working. They have managed to break a hole through the wall, and one has just slipped to the other side. Of course, if the place is filled with sand we can do nothing. I have hopes, though, that it will be clear, for how else could he have been able to pass through.'

Choking and coughing the party crept along the wall, keeping close to the base; for the smoke rose to the ceiling, and the latter being of great height gave it space in which to distribute itself. But in spite of that, the supply of air down below was small, to say the least of it. They had hardly proceeded more than ten feet when there came a cry of triumph from a point just in front of them, while the click of a metal instrument was heard.

'Come quickly. Come, Excellencies,' called the voice of the head man who controlled the excavators. 'Our comrade reports that the far side is quite clear. Some one has been at work there before us. Let us pass through at once, else we shall be suffocated.'

The words brought them rushing forward, and a gust of wind happening at that moment to sweep the smoke and flames away from the room, all saw that a hole had been cut through the wall, which being massively built, had resisted the efforts of a number of men armed with crow-bars for some time, but once the first stones were removed the rest was easy. The Professor took in the situation at a glance.

'I believe this will save the situation,' he cried, snapping his fingers, and then coughing so violently that his remarks came to a sudden ending. However, in a few moments he had regained his breath. 'See for yourselves,' he shouted, showing greater excitement than David had ever seen him display before. 'The draught enters by this hole, and is already sweeping the smoke from our quarters. It is driving the flames out into the covered way. Now, let the men pass through as quickly as possible. I shall stay here and attempt to save our goods and chattels.'

'And I too,' declared David, overjoyed that his men had been so successful. 'There are also the ponies; the poor beasts are up there in the far corner and must be almost stifled. Still, as we have lived through it, so also may they.'

'Monsieur, I also shall remain,' announced Alphonse. 'You will need helpers. I will go to the ponies.'

And go he did, with Dick creeping through the smoke after him. As for David, he seized a crow-bar, and with the help of others attacked the wall furiously. Meanwhile every one of the men who had joined them in such great haste that morning, and who to do them but justice, had shown a brave front, and had done their utmost to help in the defence, crept through the gap in the wall, each man carrying something with him. Jong and his friends too, made the most of the time at their disposal. Now that the smoke was clearing, and the heat decidedly less, they bustled about, gathering the belongings of the party, and were soon passing them through to their comrades on the far side.

'You can take it more easily now, David, lad,' sang out the Professor. 'This gap has checkmated the attempts of those fellows. There's a perfect gale coming through, and one can see nicely now, and feel quite comfortable in this atmosphere. It'll be an eye-opener to the enemy to discover us gone when the flames die down. Ah, here's Alphonse and Dick.'

One by one the latter led the ponies towards the gap, many of the poor beasts being almost exhausted. But they were able to use their legs, and were soon forced through to the far side. Then Dick and Alphonse followed David, and lastly, the Professor crept through the gap.