And what if Aisha was already dead?
That thought made Zoe’s stomach churn, but it had to be considered. The locations in his spiral were for attacks, not deaths. What if he killed her some other way, just to plan to cut her throat after the fact when the time came?
No, that didn’t feel right. It would have been too much of a symbolic gesture, a throwaway act instead of the real thing. Somehow, the real thing mattered. It had to be the act of spilling blood at the right moment, the right spot. Zoe could see that. The more she tried to get inside his head and think like he did, the better she thought she could figure out the importance he attached to things. The choice of a new day for each kill, the deliberate action of using the garrote. That had to be followed to complete the pattern.
Yet he had broken his previous MO by abducting a girl instead of finding someone on the actual night, so it was all up in the air now. She could trust her gut, but there was nothing behind it. No real evidence or fact she could put her finger on to tell her that Aisha would still be safe.
Zoe couldn’t do this alone. It was too much—so much pressure to heap onto one person’s shoulders. She would not begrudge it, not if she could save Aisha’s life. But she couldn’t get there—couldn’t finish the job. Especially not with all the local police turning on her, thinking she didn’t know what she was doing.
Zoe picked up her cell and dialed a familiar number from her contact list, hoping that the call would connect.
“Hello?”
Zoe almost sighed with relief. Hearing the voice of her mentor, Dr. Francesca Applewhite, already made her feel better, and all she had said was hello. Talking to someone who understood her completely was a salve for all of the stress.
“Dr. Applewhite,” Zoe said. “Are you free to talk?”
“Francesca, as I’ve told you a million times,” she laughed. “Yes, I’m free. I’m always free for you, even in the middle of a session. But I don’t have any appointments today. It’s Saturday.”
Zoe glanced at her smartwatch reflexively, surprised to hear the date. Time had been slipping away from her, maybe faster than she had realized. “I am sorry to disturb your weekend.”
“You don’t have to be sorry with me, Zoe. You know I don’t mind. Now, what’s bothering you?”
Dr. Applewhite always understood when Zoe needed help. “It is regarding a case I am working on,” she started, and quickly told her everything. Or at least, everything that was relevant. With it being an ongoing case, she could not use names or even give away the locations precisely. But it was worth taking the risk of being sanctioned if it meant getting some help from the one person who always knew the right thing to say.
Now Dr. Applewhite was chuckling, and Zoe could not quite understand why. “What is funny?” she asked, seeing nothing amusing at all in the tale of a serial murderer and schizophrenic.
“The pattern,” Dr. Applewhite replied. “Our boy here has it all wrong. He might be operating under delusions, but they are bigger than he realizes. He has misunderstood the reality of the Fibonacci spiral.”
“I do not understand.”
“It’s like this. The Fibonacci spiral is a theory, a formula that can be applied to many visual patterns in nature and that are naturally occurring. But the mistake the killer has made is assuming that the spiral should be perfect. In fact, in nature, it is almost always imperfect.”
Zoe frowned. “But I thought the point was that it is a specific sequence. Each number the sum of the two previous.”
“Yes, but nature is not so neat as mathematics might have you believe. Think about the instances where we can see Fibonacci spirals: a snail’s shell may grow slightly tilted. A plant’s leaves may experience growth spurts due to exposure to water or light that can throw off the pattern. A hurricane fits within the spiral, but it does not have well-defined and sharp edges. Wind forces clouds to stream back alongside the spiral itself, making a feathered edge which does not always conform exactly to the pattern.”
Zoe got the point. “So the pattern should be imperfect. But how does that help? If it is imperfect, we have even less chance of catching him.”
“No,” Dr. Applewhite said, and Zoe could almost hear her smiling. It was the same look she had always had on her face when making an important point, knowing that she was delivering important knowledge to her student. “The mistake that the killer has made is believing that the pattern should be perfect. It will be precise—exceedingly precise.”
Zoe turned this over in her head. “He is so obsessed with the pattern that he cannot see the fact that there are variances in nature. His pattern will have to be perfect.”
“Just the same way that you, my dear, sometimes find it hard to look past the numbers in order to see the variances of human nature. How you can struggle to understand the subtleties of small talk or emotional responses, because you are watching the calculations in your head.”
Zoe bowed her head slightly over the table of maps and papers. Dr. Applewhite was right. Even though she was the only person who had the ability to see things as the killer saw them, that also meant that she was victim to the same mistakes and foibles.
Being the same as a serial killer—that sent a shudder through her again.
“There is beauty in imperfection,” Dr. Applewhite continued. “Our flaws are what make us human. That’s why I have never judged you for yours. But this perpetrator… he does not see the beauty. He is incapable of looking past the numbers of the spiral itself. He objectifies it, just the same way that a serial killer looks at a victim instead of seeing a wife, mother, sister, friend. The end goal is all that matters to him. Because of this, he has made himself a predictable man.”
“You mean that we can be more precise with the calculations. Find out exactly where he intends to commit the final murders, to a much closer degree.”
“Yes. Why look at a whole town? He can only see a precise coordinate. You could take it down through decimal places, rather than looking at whole grids on the map.”
“I understand,” Zoe said, grabbing a pen. “I have the precise coordinates of each of the attacks.” She was starting to scribble out calculations, make the numbers smaller.
Dr. Applewhite laughed, a sound of joy and friendship that never failed to warm Zoe’s heart. “Hit me with the numbers.”
Zoe hadn’t thought to ask for help, but it was welcome. There was always a security to be found in your work being checked. Even though she had already completed the calculations, there was no harm in accepting the offer. She flicked through each case file to read out the coordinates to four decimal points, waiting for Dr. Applewhite to run the logarithmic function and determine precisely where the next points would be. There were only two left, and that made their job easier—they had almost all of the clues, and none of the mystery. It took time to input the data—time Zoe desperately wished she had spent earlier in the investigation—but then it was done, and they had what they needed.
“All right,” Dr. Applewhite said, after a moment’s pause for the calculations. “Take down these numbers.”
Zoe checked them against her own and saw that they matched, then used the battered old computer in the corner of the investigation room to input them in a map search. “Got it,” she said, focusing in on the square highlighted on the search. “Thirty square meters. Close enough that we can watch it all at once.”
“Well done! And will it be an easy target to stake out?”
Zoe studied the map again, checking that she had not made a mistake. “It is a diner,” she said. “It looks like the whole space is taken up by the building. I will have to check with the local authority that this map is accurate.”