She typed back a quick response:At scene now. Third victim doesn't fit the pattern. Will brief you within the hour.
The water in the chamber lapped against her boots as she turned slowly, taking in the prepared death trap that had gone unused. The killer had invested time and effort into this setup, had modified systems, opened vents, and positioned everything just right. The frustration of having their plan disrupted must have been considerable.
Which meant they'd likely be planning another attempt soon. Another victim, another carefully orchestrated death, another opportunity to use the tunnel system's infrastructure as a weapon.
"We need to figure out what connects Yamamoto to the others," Isla said, already moving back toward the tunnel exit. "Langford and Graves fit a pattern—public servants with reputations for treating people poorly. But Yamamoto breaks that pattern completely. There has to be something else, something we're missing."
They emerged into the December morning, which had brightened considerably while they'd been underground. Isla blinked in the weak sunlight, her boots squelching with thewater she'd picked up in the tunnels. Dr. Henley was already working on Yamamoto's body, her examination kit spread out on a plastic sheet, her movements methodical and efficient.
"Time of death?" Isla asked, approaching the scene.
"Based on body temperature and rigor, between 5:50 and 6:10 AM," Henley said without looking up from her work. "Which fits the security footage timeline. Cause of death is the head trauma—same pattern as Linda Graves, struck from behind with what appears to be a metal object. Probably died within minutes."
At least it had been fast, Isla thought. At least Yamamoto hadn't suffered the prolonged, agonizing deaths that Langford and Graves had endured. Though whether that was mercy or merely the killer adapting to circumstances, she couldn't say.
CHAPTER EIGHTEEN
The field office felt like a pressure cooker at 9 AM, the air thick with exhaustion and the acrid smell of burnt coffee. Isla dropped into her desk chair hard enough to make the old mechanism protest, her boots still damp from wading through the flooded tunnel where Robert Yamamoto should have died.
Three bodies in four days.
The numbers scrolled through her mind like a death toll, each victim representing not just a life lost but a pattern she couldn't quite grasp. David Langford, the difficult pipe fitter. Linda Graves, the cold social worker. And now Robert Yamamoto, the compassionate pediatrician whose murder broke every theory they'd built.
"Coffee?" James appeared in her doorway holding two cups from the break room, though from the expression on his face, he wasn't optimistic about the quality.
"Please." Isla accepted the offering, not caring that it tasted like it had been sitting on the burner since yesterday. The bitter liquid cut through the fog in her head, providing a jolt of clarity she desperately needed.
James settled into his usual chair across from her desk, pulling out his laptop with the practiced efficiency of someone who'd done this dance too many times. "Kate wants a briefing in an hour. The Director's office is breathing down her neck about the body count."
"I know." Isla had already fielded two emails from Kate and a text that had been politely worded but carried an unmistakable undercurrent of urgency. Three murders in four days looked bad. Three unsolved murders looked worse. "But I can't brief her on the progress we haven't made."
"So let's make some." James opened a new document on his screen. "What do we know for certain?"
Isla stood and moved to the whiteboard where they'd been mapping the case, studying the photographs, timelines, and connections they'd painstakingly documented. "The killer has intimate knowledge of the steam tunnel system—not just the active sections, but the abandoned ones too. They know how to navigate in the dark, how to modify temperature controls, how to prepare these elaborate death scenes."
"And they have legitimate access," James added. "The security logs show authorized entries at multiple access points, which means they're either a current city employee or someone with stolen credentials."
"Or someone whose consulting contract gives them broad access." Isla thought about Dr. Pritchard, who was under surveillance, so he couldn’t have done this. "But we need more than theories. We need maps."
She pulled out her phone and called Carol Martinez, who answered on the second ring with the slightly frazzled tone of someone dealing with a crisis.
"Agent Rivers. I've been expecting your call."
"I need complete maps of the tunnel system," Isla said without preamble. "Every section, active and decommissioned, with all access points marked. How quickly can you get them to me?"
Martinez's pause was telling. "That's... complicated. The official maps we have are incomplete. The system's been expanded and modified so many times over the decades that the documentation hasn't kept pace. Some of the older sections were never properly documented to begin with."
Isla felt frustration building in her chest, hot and tight. "You're telling me the city doesn't know what's underneath its own streets?"
"I'm telling you the city knows most of it, but not all of it. The decommissioned sections, especially, some of those date back to the 1920s. They were abandoned when we built newer systems, and nobody bothered to maintain detailed records of passages nobody was supposed to use anymore."
"But someone is using them," Isla said, her voice tight with the effort of staying professional. "Someone who knows those passages better than your official maps show them."
"I know." Martinez sounded miserable. "I'm working on compiling what we have, but it's going to take time. Maybe by the end of the day, I can have something comprehensive for you."
End of day. Another eight hours while a killer who'd already murdered three people in four days remained free to plan their next victim. Isla's hand tightened on her phone.
"Make it your priority," she said. "And Martinez? If you have staff who know the tunnels better than what's on your official maps, I need their names. Someone who's spent significant time down there, someone who'd be familiar with the abandoned sections."
