“Am I just imagining it, or is this one more delicate than the others?” I said of the feather in question.
“You’re not imagining it. It’s more delicate, more streamlined. See how the triangular structures don’t flare out quite as much?”
“Okay. Now that you’ve pointed it out.”
“And this is giving us an important hint about the bird. That’s what’s fascinating. Nature really does have a reason for things, and I’m suspicious that in this case the reason is insulation. The purpose of down is to trap air, and the finer the barbules, the more streamlined or tapered the nodes, and the more distal the location of the nodes, the more efficient the down is going to be at trapping air. When air’s trapped or dead, it’s like being in a small, insulated room with no ventilation. You’re going to be warm.”
He placed another slide on the microscope’s stage, and this time I could see that we were close. The barbules were delicate, the nodes tapered and distally located.
“What have we got?” I asked.
“I’ve saved the prime suspects for last.”
He looked pleased. “Sea ducks. And top in the lineup are the eiders. Let’s bump the magnification up to four hundred.”
He switched the objective lens, adjusted the focus, and off we went through several more slides. “Not the king or the spectacle. And I don’t think it’s the stellar because of the brownish pigmentation at the base of the node. Your feather doesn’t have that, see?”
“I see.”
“So we’ll try the common eider. Okay. There’s consistency in pigmentation,” he said, staring intensely at the screen. “And, let’s see, an average of two nodes located distally along the barbules. Plus, the streamlining for extra good insulating quality – and that’s important if you’re swimming around in the Arctic Ocean. I think this is it, the Somateria mollissima, typically found in Iceland, Norway, Alaska, and the Siberian shores. I’ll run another check with SEM, “ he added, referring to scanning electron microscopy.
“To scan for what?”
“Salt crystals.”
“Of course,” I said, fascinated. “Because eider ducks are saltwater birds.”
“Exactly. And interesting ones at that, a noteworthy example of exploitation. In Iceland and Norway, their breeding colonies are protected from predators and other disruptions so that people can collect the down with which the female lines her nest and covers her eggs. The down is then cleaned and sold to manufacturers.”
“Manufacturers of what?”
“Typically, sleeping bags and comforters.”
As he talked, he was mounting several downy barbs from the feather found inside Susan Story’s car.
“Jennifer Deighton had nothing like that in her house,” I said. “Nothing filled with feathers at all.”
“Then we’re probably dealing with a secondary or tertiary transfer in which the feather got transferred to the killer who in turn transferred it to his victim. You know, this is very interesting.”
The specimen was on the monitor now.
“Eider duck again,” I said.
“I think so. Let’s try the slide. This is from the boy?”
“Yes,” I said. “From an adhesive residue on Eddie Heath’s wrists.”
“I’ll be damned.”
The microscopic debris showed up on the monitor as a fascinating variety of colors, shapes, fibers, and the familiar barbules and triangular nodes.
“Well, that puts a pretty big hole in my personal theory,” Downey said. “If we’re talking about three homicides that occurred at different locations and at different times.”
“That’s what we’re talking about.”
“If just one of these feathers was eider duck, then I’d be tempted to consider the possibility that it was a contaminant. You know, you see these labels that say one hundred percent acrylic and it turns out to be ninety percent acrylic and ten percent nylon. Labels lie. If the run before your acrylic sweater, for example, was a lot of nylon jackets, then the very first sweaters that come off afterward will have nylon contaminants. As you run more sweaters through, the contaminant is dissipated.”
“In other words, “ I said, “if somebody is wearing a down-filled jacket or owns a comforter that got eider contaminants in it when it was manufactured, then the probability is almost nonexistent that this individual’s jacket or comforter would be leaking only the eiderdown contaminants.”