Mrs. Erskine seemed dazed. "But—but—they were all alike. All his letters were the same...And who's Jack?"
"A friend of mine who used to know Rob well—in Canada. I'm so sorry to've sprung this on you, but you ought to know it, and at least you can comfort yourself with the thought that your son never wrote such horrible letters as you have been thinking all these years. Surely someone with you must have had a motive to intercept your son's letters, and forge others in their stead."
"It's his paper—the paper he always used." Mrs. Erskine seemed quite dazed. She gave Christine the impression of a woman speaking in a nightmare.
"It may be, but it's not his letter. You see, I happen to be in a position to swear to that one, and to prove it in time. Lots of other people knew of his accident. Now, Mrs. Erskine, who is there who could have done so wicked, so cruel a thing?"
Mrs. Erskine suddenly got up, as though she found the room stifling. She looked ghastly, and to Christine she looked frightened as well.
"I must be alone—this shock—this blow—I want time"—she held out a cold, shaking hand—"will you come back—it's now five. Will you come back at seven without fail? Without fail? I—promise me you won't speak of this to anyone in the meanwhile. I know a French detective, not so far from here, before whom I want to lay the case. He is the only man who can solve this riddle. But I'll go into that later when you come back. Promise that you won't speak of it to anyone in the meanwhile. I have a feeling that absolute secrecy is essential if this mystery is to be unraveled,—and unraveled it must be—and quickly!"
Christine would have taken the widow's hand, but Mrs. Erskine did not see her gesture. There was something fierce in her eyes. Action, not sentiment, was evidently rising rapidly in her heart to the exclusion of any softer feeling. Christine mentally apologized to her for ever having thought her dull and cold.
"But what about the Inspector?" she asked gently. "You mean yon English policeman? That dolt has done nothing but muddle and muddle along. And where is he now? Away on his holidays, I shouldna be surprised."
Christine made a little deprecatory moue.
"Still, the case is in his hands," she ventured, and remembering how he had come to the help of them all at Lille, she repeated more firmly, "I do think you owe it to him to let him know about this at once."
"And where is he to be found?" Mrs. Erskine asked fiercely; "tell me that?"
Christine had not the faintest idea, and said so. She could not add that the Chief Inspector had told her to consult Mr. Watts should any emergency arise while he was away.
Mrs. Erskine sank back into her chair. "He bade me 'phone to the Prefecture if anything unexpected should happen, and it's aye the unexpected to that man that happens in all his cases, I'm thinking. Well, instead of the Prefecture, I am going, as I told you, to employ a most clever French detective of whose skill I've had some very good proofs indeed in other days. Now, Christine, my dear"—she had never called the girl that before—"just send a wire, or a letter, to your pension in Cannes and bide the night here with me. I have much to do. I need you. Leave me to myself now, but come you back at seven without fail and we will see what my Frenchman can do to clear up this dreadful discovery of yours." Mrs. Erskine was deeply moved. She folded one trembling hand over the other, as though to keep them quiet by force.
"I canna believe it"—she turned her glowing eyes on the girl—"I canna yet believe what you've told me. To-night you must let me hear anything that you remember from my Rob's letters. The letters that I never received."
Mrs. Erskine covered her face with her hands, and only made a gesture of farewell as Christine passed her.
"Don't fail me!" she breathed, and the girl laid a tender hand for a second on the bowed shoulder.
She herself spent the interval as in a dream. What did it mean? What could it mean? Was there really someone in the house with Mrs. Erskine who had substituted those brutal begging letters; but how had they been able to profit by the money? Surely there could not have been an accomplice at the other end as well? Someone who could take Mrs. Erskine's letters with their money contents and change them again for the cold, formal epistles which alone had reached Rob? Yet he had been allowed to receive the thousand pounds! Christine felt her head in a whirl, and she tried to think of something else as she walked by the sea. There was something, too, in Mrs. Erskine's manner which suggested that she knew more than she would admit. She was afraid of something, or someone. What or who? Christine was thankful that the mother could turn to an expert who could throw daylight on what seemed so dark, and to whom the other would at last speak out.
It was not quite seven when she returned to the villa.
* * * * *
IT was on the afternoon of the same day that Pointer set out for Nice. He 'phoned to Christine from Marseilles, where the train had a wait. The puzzle had yielded to the key. He knew now the truth about Robert Erskine's murder, but he wanted her help with regard to his letters to his mother.
The Chief Inspector was told that mademoiselle was out, but would be back in the afternoon. A 'phone to the Negresco informed him that Crane was away too. He wondered if he had struck the weekly meeting day of the young couple, and left a message for Christine to expect a 'phone from Nice at the hour when his train arrived. A few words over the instrument would tell him all that he wanted to know. To "Colonel Hunter" he wired instructions to meet Mr. Deane at the station.
Watts met him, but it seemed that Miss West had not yet returned to her pension. Not only that, but she had 'phoned about an hour ago to say that she was spending the night in Nice with friends, and would possibly be away a day or two. "Yes, mademoiselle had sent the 'phone herself."
"The devil!" murmured Pointer thoughtfully; "that can only mean she's at the villa! The very devil! Where's Carter?" he asked aloud of Watts, who as yet had heard nothing concerning the other's journey.
"He is to dine with the Anstruthers tonight. When I left he was playing tennis with one of the Chapman boys."
"Humph!" grunted Pointer, "we'll try to get him." Carter's voice answered him at once.
"Hello! That you, Deane? At last! Anything turned up? What? Where's Miss West? In Cannes. She was going back by the three-fifteen. Am I sure? No, I can't be sure, as she never lets me see her off. Orders, you know. But when I left her at half-past two that was her intention. Is anything the matter?"
"Not that I know of, but keep near the 'phone for a few minutes, will you?"
"You bet!" Pointer heard before he disconnected. He promptly rang up Mrs. Erskine. That lady, too, was out, Marie's voice informed him. Had Miss West been there during the afternoon? Yes, she had had tea with madame, and had left a little before six o'clock. No, she had not returned.
Again the Chief Inspector looked thoughtfully at his boot-tips. Watts, who knew his little ways, wondered what was worrying him. In another second Pointer was speaking to Carter again and asking him to come around to his hotel at once in the big car he hired regularly.
"For God's sake, tell me is there anything wrong with Christine," urged the Canadian; but the Chief Inspector hung up the receiver. He next tried to get into touch with the Prefecture, but the line was occupied, and before he got through Carter's car was at the door and that young man was in the room.
"Look here, you can't keep silence like this. What's, wrong? Why did you ask about Christine?"
"I'd like to know where she is," was all Pointer would reply. "She's not at her pension; I want to find out just where she is. Drive to the villa."
It was close on eight o'clock when the car rushed up the drive. Pierre came out at once.
"M.