Joan did not reply for a moment. Nancy looked at her with some excitement on her face. "What did you see?" she asked.
Still Joan seemed unwilling to speak, and Bobby Trench said, "If you did see something, you ought to let us know. It's a very serious business. The things stolen are worth pots of money, and we know perfectly well that it can only be Mrs. Amberley who has taken them. Besides, we've pretty well proved it now. We have found people to whom she sold separate pearls; but for goodness' sake don't let that out yet. I only tell you so that you may know that it wouldn't only rest on you."
Joan raised her eyes to his. "I went into the morning-room," she said, "and Mrs. Amberley was standing with her back to me by the fireplace."
"By Jove!" exclaimed Bobby Trench, staring at her as if fascinated.
"She turned sharp round when I came in," said Joan, "and then she asked me if I didn't love old Dutch pictures, and showed me that one. That is why I remembered about it."
"Was she actually looking at it when you came in?"
"Well, no. I don't think she was. It was just a little to the right of where she was standing. I had forgotten all about it, but I remember now that when she mentioned the picture I thought to myself that she seemed to have been looking at the bare panels, and not at the picture at all. Besides, she was blushing scarlet, and it was just as if I had caught her in something."
"By Jove! you must jolly nearly have caught her with the panel open. Did you notice anything odd about the wall she was standing in front of as you came in?"
Joan thought for a moment. "No, I didn't," she said decidedly.
"Had she got anything in her hand?"