“Correct. We were hoping you could answer that question. Why was your fingerprint on that envelope?”

Barbara looked baffled. “I haven’t the foggiest idea,” she said. “Isn’t that the sort of thing you gentlemen are supposed to find out?”

“It is,” Morales said.

“Well, when you do, I shall be very curious to learn how that happened.”

“We are inclined to think that your fingerprint was placed on the envelope when you handed it to Mr. Gregg,” Morales said.

Croft watched the woman with fascination, but he said nothing.

“Gentlemen, let me be perfectly clear,” Barbara said. “I do not now nor have I ever known this Mr. Gregg, and so it follows that I have never handed him an envelope, let alone one containing money.”

“Mrs. Grosvenor, we are aware that you have been accused of murder in the past.”

“Then you must be aware that I was found innocent,” she replied smoothly. “Gentlemen, I must lay all of this at the feet of my former husband, Mr. Eagle. He has been saying for years that I am trying to kill him, when nothing could be further from the truth. I’m afraid that, during all that time, I am told by professionals, he has exhibited symptoms of severe paranoia. I have nothing to gain from his death. We have been divorced for many years, and I asked nothing of him at that time. I am very much more wealthy than he, so there could be no financial motive, and I bear him no ill will, except for these ridiculous charges of his, for which there has never been a shred of proof. I’m very much afraid that the best explanation for this airplane explosion is that Mr. Eagle hired this Mr. Gregg to blow it up, so that he could make yet another baseless charge against me.”

“Then how do you explain the fingerprint on the envelope?”

“When Mr. Eagle and I were married, I often typed correspondence for him. It is entirely possible, even likely, that he possessed an envelope bearing my fingerprint, one that he has preserved for this special occasion. Now, have you any other questions for me? I’m expecting guests for dinner, and I have to consult with the cook about the menu and then change.”

“No, Mrs. Grosvenor,” Morales said. “We have no other questions—at this time. But you may expect to see us again.”

Barbara stood up, and the detectives stood with her. “Then I bid you good evening, gentlemen.”

The large young man had appeared silently at the door to the library, and he escorted them to the front door. “Good evening, gentlemen,” he said, closing it behind them.

“Well,” Croft said, “Captain Clark was right—she is the coldest, smoothest bitch ever to come down the pike.”

“Yes,” Morales said, “and she blew our fingerprint evidence right out of the water. Given her reasoning, it would never convict her.”