Zoe’s head snapped up sharply. “You cannot tell anyone,” she said. “Not about me. It is between us, as partners. No one else can know.”
Shelley hesitated, but caught Zoe’s eye and nodded.
“Promise me,” Zoe said.
Shelley wet her lips before answering. “I promise. It will take some thought to present this in a way that makes sense without people knowing what you can see, but I won’t say anything. So long as you promise me something, too.”
“What is it?”
“Not to keep anything from me. If you can see something, tell me,” Shelley said. She shook her head, although there was still a smile on her face. “I just thought about the guy we caught the other day, in the desert. How you knew where he was going to be, and everyone thought you were wrong. You could see it, couldn’t you?”
“Plain as day.” Zoe took a deep breath. “All right. I promise that I will tell you everything from now on, in relation to our investigations.”
The clarification was necessary. Zoe didn’t want to promise to tell Shelley literally everything. That would have been too much.
“Shake on it, partner?” Shelley held out her hand with a twinkle in her eyes.
Zoe shook, and the deal was done.
“Now, let’s get some more precise maps, and we can start figuring out the exact coordinates where we need to keep watch,” Shelley said, getting up and moving toward the computer already.
Zoe finished the last line over an hour later, taking her ruler away and examining her handiwork. It was clean and precise, just the way she needed it to be. Not a single mistake. Zoe had always been good at precision. It wasn’t so hard, when you could already see the lines and angles and calculations laid out on the page for you, before you put them down in ink.
“Right,” Shelley said, standing back. “They’re all lined up exactly.”
They stood for a moment to take in the maps of the three Midwest states that the killer had already targeted, placed in precise relation to one another across all of the tables they had been able to find and push together. These maps were much clearer. They were able to differentiate more clearly the precise locations of each kill, rather than a wider point that took in other buildings and roads.
Zoe lifted the sheets of tracing paper she had managed to find in the desk of one of the sheriff’s deputies, who was apparently a bit of a craft enthusiast. Over it, Zoe had been drawing a perfect grid of squares with her trusty ruler, while Shelley printed and stuck the map pages together. Now, she laid the grid over the top of the map, making sure that the points each lined up with the murder locations.
She took a pen in a different color and drew the spiral again, connecting the kill sites in chronological order. She did not really need the grid to know where the line had to flow, but it was there for Shelley’s benefit.
“Here, we can see that our killer is operating in a reverse Fibonacci spiral, starting from the furthest point and working his way down,” Zoe said as she drew. “Now, watch. The spiral moves across the grid in a predictable manner, so we can work out precisely where it will finish. It passes through these points—here, here, and here.”
Zoe drew a circle around each of the last three locations needed to finish the job.
“He started wide to try and avoid running into suspicion for as long as possible,” Shelley guessed, her fingers tracing the first murder sites. “With Kansas, Nebraska, and Missouri involved, it was going to take a while for the states to work together. And it did. Four murders before we even got here, and one since. He must have suspected that we would track him down quickly once we saw that the murders were all connected.”
“Even though he is careful to remove traces of himself, and even though the locations are free from surveillance, there was always a chance that he would be seen in some way,” Zoe agreed. “His car could have been identified on the road. Spreading wide at the beginning and then focusing down was the best way to give himself a chance of getting it all done.”
“But now he will be operating in a much smaller area. Which is good news for us.”
“And the locations will be even more precise. We will be able to narrow it down perfectly.”
Shelley pressed the tracing paper down, ensuring she could read through it. “The next kill site is a roadside attraction… what does that say? I think some kind of fair. Then we have a little town circled—oh, no, that one will be so much easier for him! And then it looks like the last one is just… open ground? Nothing there in particular.”
Zoe followed Shelley’s discoveries, thinking. “We only have to stop him once. We stake out the fair tonight. It is not about where the body will be left, but where the actual killing will be done. We have to catch him in the act.”
“That’s not going to be easy,” Shelley said, playing with her pendant, worrying it back and forth around her neck.
“We still have to try,” Zoe said. “Get him tonight, before he strikes the town. I will call the Kansas state police chief and organize a briefing. We have to mobilize now.”
Zoe watched the assembled twenty-four men and women with a twitchy feeling of anticipation. Her mind was working in overdrive, scanning them for details. The full two centimeters that one trooper’s moustache grew over the edge of his lips. The youngest trooper in the room, at twenty-one, and the oldest easily in his mid-forties. The way that societal hierarchy had granted the chief of police a chair at the front of the room in the very center, while those keen for promotions ensured to sit as close to him as possible.
“We believe that the killer will be targeting this location next: the Kansas Giant Dinosaur Fair,” Shelley announced, standing in front of the map they had blown up for the briefing. “I’m sure those of you who are local are familiar with it, but in summary, it’s a permanent roadside attraction with around twenty giant dinosaur statues. Around these are a number of carnival games, food stalls, memorabilia stands, and so forth.”
“The bad news,” Zoe said, taking over, “is that tonight is a special Family Night event. The fair will be running a number of special features, as well as a discounted entry fee for groups of three or more. This means there will likely be a high number of people in attendance, making our jobs that much harder.”
“Why don’t we shut down the fair?” one of the local troopers asked, raising his hand.
“We do not want to spook him,” Zoe replied. “Remember that he will not just be planning to strike tonight in this location, but also at other locations in the future, judging by his track record thus far. If we stop him from killing tonight, we save a life. But if we catch him tonight, we stop him from killing ever again.”
Shelley took over. “We have a little information to go on, which should make it easier to track down our man. We’ll focus on the parking lot, as we know what kind of car we’re looking for. It’s an older-model green sedan, with likely with out-of-state license plates. To be sure, we will be tracking all sedans fitting the description and watching the drivers. We are looking for a male suspect, likely traveling alone.”
“What if he’s changed his car?” This time from another trooper.
“We have no reason to believe he knows we have identified his car,” Shelley said. “Besides which, that’s our only lead. We don’t know what he looks like in any particular, even down to his race. We have no living witnesses. We have to focus on the car by dint of having nothing else to go on.”
“How do you want us deployed?” asked the chief of police.
“We will need to avoid suspicion,” Zoe said, moving the map aside to show a diagram of the attraction and its parking lot. “This man is a habitual killer, which means he will kill again if he is not stopped tonight. We cannot risk spooking him. If he runs, there is no guarantee that we will find him again. Myself, Special Agent Rose, and eight further state troopers will take the parking lot, in plain clothes. Ten of you will walk through the fair and blend with the rest of the attendees, looking for any suspicious behavior. The rest of you will wait in unmarked cars at these locations, here and here, further down the road. Your task will be to form a cordon if he manages to leave the parking lot.”