The manservant, who had left the room, now returned, carrying a large pumpkin in both arms. He set it down on the hearth before the fireplace.
“It is true, Sergeant D’Agosta, you would have been a much more effective demonstration. But it would have caused such a mess.” Fosco went back to assembling the device.
D’Agosta moved slowly backward, slipping his gun back into his holster as he did so. Somehow, the act of drawing his weapon brought fresh resolve. He and Pendergast were both armed. At the first indication of trouble, he would have no hesitation about taking out both the count and Pinketts. Except for some kitchen help, there didn’t seem to be any other servants around—but he knew that, with the count, appearances were deceptive.
“There we go.” Fosco hefted the assembled machine, which looked something like a large rifle, made primarily of stainless steel, with a bulbous dish at one end and a barrel sporting half a dozen buttons and dials at the other. “As I said, I knew I had to kill Grove and Cutforth in such a way that the police would be utterly baffled. It had to be done with heat, of course. But how? Burning, arson, boiling—much too common. It had to be mysterious, unexplainable. That was when I recalled the phenomenon known as spontaneous human combustion. You know the first documented case of it was here in Italy?”
Pendergast nodded. “The countess Cornelia.”
“Countess Cornelia Zangari de’ Bandi di Cesena. Most dramatic. How, I wondered, could a similarly devilish effect be duplicated? Then I thought of microwaves.”
“Microwaves?” D’Agosta repeated.
The count smiled patronizingly at him. “Yes, Sergeant. Just like your own microwave oven. They seemed perfect for my needs. Microwaves heat from the inside out. They can be focused, just like light, to—say—burn a body while leaving the rest of the environment intact. Microwaves heat water far more selectively than dry materials, fats, or oils, so they would burn a wet body before heating the rugs or furnishings. And they have an ionizing and heating effect on metals with a certain number of valence electrons.”
Fosco ran a hand over his device, then laid it on the table next to him. “As you know, Mr. Pendergast, I’m a tinkerer. I love a challenge. It’s quite simple to build a microwave transmitter that would deliver the necessary wattage. The problem was the power supply. But I. G. Farben, a German company which my family was connected with during the War, makes a marvelous combination of capacitor and battery capable of delivering the requisite charge.”
D’Agosta glanced at the microwave device. It looked almost silly, like a cheap prop to an old science fiction movie.
“It would never work as a weapon of war: the top theoretical range is less than twenty feet, and it takes time to do its work. But it suited my purposes perfectly. I had quite a time working out the kinks. Many pumpkins were sacrificed, Sergeant D’Agosta. At last, I tested it on that old pedophile in Pistoia—the one whose tomb you examined. There was a bit of a meltdown—the human body takes a lot more heating than a pumpkin. I rebuilt the device with improvements and used it more successfully on the terrorized Grove. It wasn’t quite enough to set the man on fire, but it did the job. Then I arranged the scene to my satisfaction, packed up, and left, locking everything and turning the alarm back on. With Cutforth it was even simpler. As I said, my man Pinketts had rented the apartment next door and was undertaking ‘renovations.’ He made a marvelous elderly English gentleman, poor man, all bent over and muffled up against the chill.”
“That explains why they couldn’t identify a suspect from the security video cams,” D’Agosta said.
“Pinketts used to be in the theater, which frequently comes in handy for my purposes. In any case, the weapon works beautifully through walls made of drywall and wooden studs. Microwaves, my dear Pendergast, have the marvelous property of penetrating drywall like light through glass, as long as there is no moisture or metal. There could of course be no metal nails in the wall between the two apartments, because metal absorbs microwaves and would heat up and cause a fire. So Pinketts opened our side of the wall, removed the nails, and replaced them with wooden dowels. When it was all over, he put our side of the wall back up. The whole operation was disguised as part of the remodeling job. Pinketts himself did the honors on Cutforth while I was at the opera with you. What better alibi than to contrive to spend the evening of the murder with the detective himself!” Fosco heaved in silent mirth.
“And the smell of sulfur?”
“Sulfur burned with phosphorus in a censer, injected through the wall at cracks around the molding.”