“It is not merely that I love Mimi, but I have reason to look on Lady Arabella as her enemy,” Adam continued.

“Her enemy?”

“Yes.  A rank and unscrupulous enemy who is bent on her destruction.”

Sir Nathaniel went to the door, looked outside it and returned, locking it carefully behind him.

CHAPTER XX—­METABOLISM

“Am I looking grave?” asked Sir Nathaniel inconsequently when he re-entered the room.

“You certainly are, sir.”

“We little thought when first we met that we should be drawn into such a vortex.  Already we are mixed up in robbery, and probably murder, but—­a thousand times worse than all the crimes in the calendar—­in an affair of ghastly mystery which has no bottom and no end—­with forces of the most unnerving kind, which had their origin in an age when the world was different from the world which we know.  We are going back to the origin of superstition—­to an age when dragons tore each other in their slime.  We must fear nothing—­no conclusion, however improbable, almost impossible it may be.  Life and death is hanging on our judgment, not only for ourselves, but for others whom we love.  Remember, I count on you as I hope you count on me.”

“I do, with all confidence.”

“Then,” said Sir Nathaniel, “let us think justly and boldly and fear nothing, however terrifying it may seem.  I suppose I am to take as exact in every detail your account of all the strange things which happened whilst you were in Diana’s Grove?”

“So far as I know, yes.  Of course I may be mistaken in recollection of some detail or another, but I am certain that in the main what I have said is correct.”

“You feel sure that you saw Lady Arabella seize the negro round the neck, and drag him down with her into the hole?”

“Absolutely certain, sir, otherwise I should have gone to her assistance.”

“We have, then, an account of what happened from an eye-witness whom we trust—­that is yourself.  We have also another account, written by Lady Arabella under her own hand.  These two accounts do not agree.  Therefore we must take it that one of the two is lying.”

“Apparently, sir.”

“And that Lady Arabella is the liar!”

“Apparently—­as I am not.”

“We must, therefore, try to find a reason for her lying.  She has nothing to fear from Oolanga, who is dead.  Therefore the only reason which could actuate her would be to convince someone else that she was blameless.  This ‘someone’ could not be you, for you had the evidence of your own eyes.  There was no one else present; therefore it must have been an absent person.”

“That seems beyond dispute, sir.”

“There is only one other person whose good opinion she could wish to keep—­Edgar Caswall.  He is the only one who fills the bill.  Her lies point to other things besides the death of the African.  She evidently wanted it to be accepted that his falling into the well was his own act.  I cannot suppose that she expected to convince you, the eye-witness; but if she wished later on to spread the story, it was wise of her to try to get your acceptance of it.”