“Tiny,” Anna helped her out.
“Tiny. So each tiny bit is in its own tiny tube of gel in the tiny bowling alley. All in a line like the lanes.” She was warming up to the bowling alley and waited till Anna nodded her understanding before she went on. “Then the little bits are pushed down the tube full of gel – the lane – with the same amount of pressure. I mean it’s not pressure, it’s electricity. It’s called gel electrophoresis…”
“I get the idea,” Anna said. “All the DNA bowling balls are rolled down their individual lanes with the same amount of force.”
“Okay. That will work. The lighter ones go farther along the gel tubes than the heavier ones. When they all stop, you look at a readout; it looks sort of like a shadowy version of the old computer punch cards. A series of marks. Like on television when they lay one DNA readout over the other and all the marks are exactly the same and – Bingo! – you’ve got the criminal.
“The lab at Michigan Tech has the DNA fingerprints for all of the wolves on Isle Royale. Whenever there’s a kill, a biotech or one of the Winter Study guys collects samples from the scat. Over time, they’ve built up a database on each of the wolves. Those ‘fingerprints’ are now in this smaller computer. When I put in the sample from the blood or the follicles that we took today,” she nodded toward the wolf melting into the newspapers at their feet, “I’ll be able to tell where he’s been – at what kills – which pack he belonged to, if he’d ever been at another pack’s kill, things like that.”
In law enforcement, Anna often had to wait weeks for DNA tests to come back, and the kind of detail Katherine was talking about was exorbitantly expensive. Often, up to fifty separate tests had to be run.
“Interesting,” she said noncommittally.
Katherine heard the skepticism and cast back over her words to see where she’d gone wrong. When she wasn’t guarding, which she did whenever a member of the opposite sex was in the room, she was easy to read. Emotions passed just under the skin the way they do on the faces of very young children, leaving ripples in the eyes and mouth.
“The PCR is a portable DNA fingerprinting device,” she said.
The machines Anna had seen that tested for DNA markers were huge, computers and other paraphernalia taking up entire walls.
“I first worked with one in the Northwest. Salmon. The fishermen can take only one kind and not the other, but you can’t tell which fish is which by looking at them. We used an earlier version of the PCR. The reason it can work is that it doesn’t do much. You set it to figure out just one or two things. Like the DNA for the two species of fish. Both fingerprints are known quantities and are already loaded in the PCR’s computer. So when you feed it the new sample, all it has to do is compare it with those already on file; it doesn’t have to figure out anything.
“What this PCR does is simply show me the readout, what kind of line the balls make; that’s that wolf’s ‘fingerprint.’ All the ISRO wolves’ fingerprints are in this machine, so the fingerprint I get is compared to the existing fingerprints. Each existing fingerprint represents a wolf and each wolf has been assigned a number. I can look at my readout and see that number such and such left my sample. Or, in this case, is my sample. Then I e-mail the lab at Michigan Tech and add my data to theirs. Then they can look back in their files and see that my wolf – this wolf – ate a moose, say, at Rock Harbor in the winter of 2005 because somebody collected scat there at that time and its DNA matched the DNA I collected. Do you see?”
She looked so desperate Anna might have said she understood even if she didn’t. “I get it,” Anna said. “We do it with regular fingerprints. They’re run through a national database and, if they match up, we know where our guy was when he left his print behind.”
Relieved, Katherine went back to her machine. Anna watched for a while, but it was a one-woman show. Returning to the wolf, she crouched near its head. Fluids were beginning to seep from the corpse as it thawed. Before the animal was anywhere close to room temperature, the bunkhouse was going to smell like roadkill on a hot afternoon.
Until the blood matted and the fur at the throat could be separated, the killing wound – or wounds – was impossible to see. Anna guessed the other wolf got in a lucky hit and punctured the carotid artery early in the fight. That would account for the fact that there were no lesser or defensive wounds – at least none she could see.
The door to the front room banged and Anna rose. “Robin and Adam,” she said. Without being aware she was doing it, Anna had been listening for their return. Unconsciously she’d been gauging the level of light, the cold, the freshening wind and listening for the radio. Suddenly angry, she demanded of Katherine, “Did you hear Robin radio in?”
“I don’t think Robin carries a radio,” Katherine said distractedly.
The woman’s interest was gone to scat. Anna left her.
SCAT WAS THE TOPIC OF CONVERSATION at the dinner table. Robin and Adam had not seen Middle pack as it fled Washington Harbor, but they’d come across their tracks. Over dinner – a casserole Ridley had concocted with pasta, frozen peas and chicken – Robin outlined her path.
“We hiked toward Malone Bay. We got as far as the last ridge before you go down to Siskiwit,” Robin said in her soft cheery voice.
Eight or nine miles, if Anna remembered correctly.
“Then we split up, and I came back cross-country. Lots of swamps. Downed stuff. I saw moose tracks, then I came across the wolves’ trail and followed them back. What scared them off the harbor?”
“We ran out of water,” Ridley said in the shorthand of the island.
Anna was still doing the math. Came back cross-country. Add a couple of miles to the return trip. Nine miles out, eleven or twelve back.
“We got tons of samples. They’re in the kitchen with the wolf.”
Twenty miles of rough country, freezing temperatures, carrying a backpack full of shit.
Comforting herself with the knowledge that Robin was nearly a quarter century younger than she and an Olympic contender, Anna submerged her consciousness in the food. She was just short of shoveling it in, minding her table manners only by an act of will. Calories being units of heat, a concept she’d learned in high school chemistry class, was finally making sense.
“I wish I’d had a camera,” Robin said around a mouthful of toast with peanut butter and jam – a side dish served with every meal.
“One of the wolves had huge feet. Like twice as big as the others. Then, about halfway between Siskiwit and Windigo, they aren’t there anymore. It must have joined the pack on a rocky place. I looked for its tracks all the way back but couldn’t find where it had caught up with the others.”
“Twice as big?” Bob said with a lifted eyebrow and an avuncular smile.
Katherine ducked her head, letting her hair fall over her face in a screen. Robin stared straight into Menechinn’s eyes. “Twice as big,” she said without a hint of defensiveness. Anna smiled. Olympic training had toughened more than the girl’s body.
“That’s your work tomorrow,” Ridley said. “I’ll give you the camera.”
“How about you, Adam? Did you see tracks twice as big as a normal wolf’s?” Bob asked. He winked at Robin to show there were no hard feelings.
“We’d split up, remember?” Adam said neutrally.
“Why don’t you go out with Robin tomorrow,” Ridley suggested to Bob. “See for yourself. I’m sure Robin could use somebody to carry the camera.”
Robin took a huge bite of toast to cover her smile. Given the chance, Anna guessed she could – and would – hike Menechinn into an early grave.