Before Carstairs could reply Anstice spoke rather diffidently.

"I have just one suggestion to make, Major Carstairs. Am I right in supposing you are staying down here to-night?"

A fleeting embarra.s.sment was visible on the faces of both Major Carstairs and his wife; but the former answered resolutely:

"Yes. I am certainly hoping to stay here."

"Well, if I might just make a suggestion, why not give out that you are returning to town to-night and coming down to stay to-morrow or the next day? Tochatti would probably, thinking this her last opportunity, make haste to seize it and write another letter or two--possibly the last--to-night."

"You mean give out that I am returning to town to-night; start, in fact, in reality, and come back later, when the house is quiet?"

"Yes," said Anstice, wondering what the soldier thought of his amateur strategy. "Then you--and anyone else you choose--could sit up here and wait events."

"I admire the simplicity of your plan, Dr. Anstice," returned Carstairs with an irrepressible laugh. "I've been called upon to exercise diplomacy at times myself, but I don't think I ever hit on anything more telling in the way of a plan than this charmingly simple one of yours!"

"You approve of it, then?" Anstice was in no wise offended by the other's mirth.

"Highly--it's just the plan to appeal to me," said Carstairs, still smiling infectiously; and Chloe rose from her couch and coming to his chair seated herself on the arm and rested her hand on his shoulder.

"I know why the plan appeals to you, Leo! It recalls your schoolboy days, when you pretended to go to bed and then stole out to skate by moonlight!"

"Hush, hush, Chloe! Never tell tales out of school," commanded the Major in mock alarm; but Anstice noticed how the man's brown fingers closed round his wife's hand, and suddenly he felt as though this spectacle of their reunion was too tantalizing to be pleasant to a sore heart like his own.

He rose rather abruptly, and both the others looked at him with a little surprise.

"You're not going, Anstice? Surely you'll stay to dinner? My little daughter will be sorely disappointed if you run away now!"

"Do stay, Dr. Anstice!" Chloe rose too, and her eyes, like two beautiful blue jewels, shone kindly into his. "Our scheme will have to be discussed further, won't it? We mustn't take the field with an ill-prepared plan, must we, Leo?"

"Indeed we must not," returned her husband quickly. "Especially as I was going to ask a very big favour of you. Dr. Anstice! Seeing how more than good you have been in interesting yourself in this affair, I have been wondering whether you wouldn't conceivably like to be in at the death, so to speak. In plain words, I was going to ask you if you would care to be my fellow-conspirator in this nefarious plot we have hatched between us!"

"You mean--will I sit up with you to-night?" Anstice spoke eagerly, and Chloe smiled.

"Well, you're not annoyed by the suggestion, anyway! I needn't say I should appreciate your company--though after all, it is a big thing to ask a man of your calling to sacrifice the rest he must need pretty badly!" He spoke rather dubiously.

"Oh, not a bit of it, Major Carstairs!" Anstice's eyes brightened at the thought of the adventure. "In a matter of this kind two witnesses are better than one; and there is always a chance that even a woman may turn nasty when she finds herself cornered--especially one who is half a foreigner," he added with a smile.

"Then you'll come? It's awfully good of you----"

"Not at all, sir. You forget I'm an interested party," said Anstice quickly. "It is as much to my interest to clear the matter up as to yours, now. Well, what about details? Where--and how--shall we meet, and how do we get into the house without anyone knowing?"

"Ah, yes. That requires thought."

Major Carstairs rubbed his hands together gaily, and Chloe burst out laughing.

"You two are nothing but schoolboys," she said joyously. "I believe you are both looking forward to this midnight adventure! You'd be quite disappointed if there were no need for your masterly plot after all!"

Anstice and Major Carstairs looked rather shamefacedly at one another; but Chloe was merciful and restrained further mockery for the time.

"Well, now I will make my suggestion," she said. "Leave the house in the usual way, by the front door; and come back, at whatever hour you agree upon, to the window here. I will let you in myself, and not a soul need know you have re-entered the house."

"Very well," Carstairs nodded. "One suggestion though. Leave the window open--no one will see behind those curtains, and go to bed as usual yourself. Depend upon it, if Tochatti is really the culprit, she will take all means of satisfying herself that you are safely in bed before she begins her work, and it would not do for her to find your room empty at midnight."

Chloe paled a little, and when she spoke her voice was uneasy.

"Leo, do you really think Tochatti is so--so malicious? I can't bear to think of her being with Cherry--she is with her almost night and day, you know--if she is so dreadful, so dangerous a character----"

"You need not be afraid, Mrs. Carstairs." It was Anstice who spoke, rea.s.suringly. "The little one is quite safe with her, I am sure of that.

If it really does turn out that Tochatti has been to blame, I feel convinced that we shall find she is not altogether responsible for her actions----"

"But that's worse still!" Chloe's voice was really alarmed. "If she is mad--a lunatic----"

"I did not mean quite that," said Anstice. "I meant--well, it is rather a difficult subject to enter into at a moment's notice; but--have you ever heard of a dual personality?"

"A dual personality?" She repeated the words, her white brow wrinkling with the effort of concentration. "I think I know what you mean--a person with two sides to his character, so to speak--of which first one is in the ascendant and then the other?"

"Kind of Jekyll and Hyde business, what?" Major Carstairs knew his Stevenson, and Anstice nodded.

"Well, something like that, though not so p.r.o.nounced. There really are such people, you know--it is not only a fantastic tale that a man may lead a kind of double life, speaking in a spiritual and not a physical sense. You don't call such people lunatics, nor are they, save in extreme cases, criminals. But it is quite possible for a woman like Tochatti to devote one half of herself to your service--and serve you admirably!--and lead what seems in all respects an open and above-board existence; and yet, through some kink in her character, stoop to an action one would expect to find only in a woman of a thoroughly debased nature."

He paused, but neither of his hearers spoke.

"It is as if a lower spirit entered into these people at times, driving them to do things which in a normal state they would be quite incapable of doing. You know the old Biblical theory of possession? Well, the same thing, under another name, is to be met with to-day; and for my part, when I come across the case of a person whose present behaviour contradicts all the actions of his previous life, upsets all the data, so to speak, which I have been able to gather of his conduct in the past, well, I put it down, mentally, to that peculiar theory of 'possession' with which the Easterns in the time of Christ were apparently perfectly familiar."

"As they are to-day," said Major Carstairs unexpectedly; and Anstice looked gratified at the corroboration. "It is a strange theory, I own, but after what I have seen in India I confess I find it perfectly feasible."

"And you think my poor Tochatti may be a victim to this old form of demonism?" Chloe addressed the question to Anstice, and he answered it after a momentary hesitation.

"Well, it is too soon to make any sweeping statement of that kind, Mrs.

Carstairs, but I must acknowledge it is hard to reconcile the woman's general behaviour with an action of this kind without some such theory.

However"--he glanced at the clock--"if you will excuse me I must really get home. There will be all sorts of complaints from my surgery patients if they are kept waiting!"

"One moment, Anstice! I take it you will come back to-night? Though really it is a jolly big thing to ask...." Major Carstairs tone was apologetic.

"Of course, and we must settle where we meet. But first, shouldn't we let Tochatti know that you are not staying here to-night?"

"Why, yes." Chloe moved towards the boll. "I'll send for Cherry--that will bring Tochatti--and you can allude to your departure then."

Three minutes later Tochatti appeared, in charge of the excited Cherry, who flew at Anstice, and, quite regardless of her immaculately frilled muslin dress, flung herself into his arms and kissed him demonstratively.

"Oh, my dear, what _ages_ since I've seen you!" Her tone was a faithful copy of the parlourmaid's greeting to a recent visitor to the kitchen.

"Are you going to stay to dinner? I do hope so, 'cos I'm going to sit up and there's lovely things--lots of roasted pheasants and meringues all filled with squelchy cream!"

"Alas, Cherry, I can't stop!" Anstice's comically regretful tone made Chloe smile. "I shall have to go home and see my patients. And if I get a chop----"

"_And_ a chipped potato, my dear," prompted Cherry.

"_And_ a chipped potato," concurred Anstice obediently, "I shall think myself lucky! But I wish you hadn't told me there were to be lots of pheasants!"