Adam’s comment pleased the old gentleman.

“I have it in my bones, sir, that you have struck—or rather reasoned out—a great truth.”

Sir Nathaniel went on cheerfully. “When the world of commerce wakes up to the value of your find, it will be as well that your title to ownership has been perfectly secured. If anyone ever deserved such a gain, it is you.”

With his friend’s aid, Adam secured the property without loss of time. Then he went to see his uncle, and told him about it. Mr. Salton was delighted to find his young relative already constructively the owner of so fine an estate—one which gave him an important status in the county. He made many anxious enquiries about Mimi, and the doings of the White Worm, but Adam re-assured him.

The next morning, when Adam went to his host in the smoking-room, Sir Nathaniel asked him how he purposed to proceed with regard to keeping his vow.

“It is a difficult matter which you have undertaken. To destroy such a monster is something like one of the labours of Hercules, in that not only its size and weight and power of using them in little-known ways are against you, but the occult side is alone an unsurpassable difficulty. The Worm is already master of all the elements except fire—and I do not see how fire can be used for the attack. It has only to sink into the earth in its usual way, and you could not overtake it if you had the resources of the biggest coal-mine in existence. But I daresay you have mapped out some plan in your mind,” he added courteously.

“I have, sir. But, of course, it may not stand the test of practice.”

“May I know the idea?”

“Well, sir, this was my argument: At the time of the Chartist trouble, an idea spread amongst financial circles that an attack was going to be made on the Bank of England. Accordingly, the directors of that institution consulted many persons who were supposed to know what steps should be taken, and it was finally decided that the best protection against fire—which is what was feared—was not water but sand. To carry the scheme into practice great store of fine sea-sand—the kind that blows about and is used to fill hour-glasses— was provided throughout the building, especially at the points liable to attack, from which it could be brought into use.

“I propose to provide at Diana’s Grove, as soon as it comes into my possession, an enormous amount of such sand, and shall take an early occasion of pouring it into the well-hole, which it will in time choke. Thus Lady Arabella, in her guise of the White Worm, will find herself cut off from her refuge. The hole is a narrow one, and is some hundreds of feet deep. The weight of the sand this can contain would not in itself be sufficient to obstruct; but the friction of such a body working up against it would be tremendous.”

“One moment. What use would the sand be for destruction?”

“None, directly; but it would hold the struggling body in place till the rest of my scheme came into practice.”