’Yes. It works the engines which collect and store the electric power.’ ’Exactly; and it cannot be used for any other purpose. It is of no use, for instance, for drinking purposes, because the water has a disagreeable, brackish taste. Therefore, there is a well of fresh water. Is it not so, sir?’ ’True,’ returned Ivanta, eying him keenly. ’But what of that?’ ’That well was made by boring downwards till a stream of pure water was found. When this was met with it rushed into the bottom of the well and found its own way out, thus affording an ample supply for the garrison without further trouble. So no one bothered himself further about it as to whence the stream came or whither it went. But all that was many years ago. Since then, however, this fresh-water stream has been gradually drying up; and now there is not enough to supply the people on guard there. That is one reason why the garrison is now so small. Then another well was bored in another part, which gave a sufficient supply for the reduced garrison, and the very existence of the first well was almost forgotten. But where the stream once ran there is now an underground passage or tunnel, which starts from a grotto high up in another part of the mountain.’ Ivanto started. ’Say you so? Are you sure?’ he exclaimed. ’Certain am I of what I say, oh king! No one seems to have noted that the drying up of this stream has opened a back way, so to speak, into the stronghold, which renders it possible to attack it by a surprise visit. No one seems to have troubled about it, or to have made it his business to report that so simple a fact has rendered useless all the work and time and trouble expended upon your elaborate defences.’ At this Ivanta frowned a little; then a smile passed over his countenance, and he cried, ’Said I not that you were a man after my own heart, friend Fumenta? Of a truth, the next time I design a fortress I shall ask you to look at my plan, and tell me of all its weak points before I carry it out. But this seems to happen most fortunately for us. Do you mean to say we can make our way in by the channel of that dried-up watercourse? Can you guide us to it?’ ’That is my plan. It is a very simple one, after all,’ returned the outlaw chief modestly; ’but I think you will find that it will suffice for our purpose. I suggest that you send out two parties, one to attack the place in front, while I will guide the rest, so that they can creep in by the route I have indicated. The other party must show no sign till we have gained the interior and manipulated the levers which cut off the electric current from the doorways. Then they can make a dash and help us to overpower the garrison.’