My heart started pounding.

This marble was the first piece of physical evidence since Zeke disappeared. Why was it on my doorstep? Had he left it himself as a signal, or was the kidnapper taunting me?

The janitress.

Immediately, I tagged the property manager in the residents' group chat. "Send me the full list and photos of all cleaning staff on duty recently. ASAP!"

The property manager, clearly terrified, didn't delay. A few seconds later, a list appeared. The photo showed a janitress named Jane Miller, in her 50s, with a face that looked honest and reliable.

I posted the screenshot to the group. "@everyone, does anyone know Ms. Miller? Which floors does she clean? Where is she now?"

Replies came in almost instantly.

"Ms. Miller is very nice and hardworking."

"She's responsible for the high-rise section, floors 12 to 22."

"I don't think she came in today."

A foreboding hit me immediately. I switched screens and began tracking into the citywide traffic monitoring system.

My husband, Sam Murphy, was a cybersecurity architect. Over the years, just by being around him, I had picked up a few tricks myself. The tools he left on our home computer became top-tier weapons in their own right.

I typed in Jane's ID number from the property manager. Almost instantly, I pinpointed her address, a rundown urban village.

Meanwhile, Officer Holt was also taking action. "Sophia, we've already sent people to find this janitress. Don't get worked up—it could just be a coincidence."

Coincidence? I didn't think so.

I tracked the police cars heading toward the village while keeping a close eye on the residents' group chat. The countdown for the second hour had just ten minutes left.

Dr. Lynch suddenly posted a long message in the group.

"Ms. Watson, I understand a mother's feelings. How about this? I'm willing to offer one million as a reward for anyone who provides a lead on your boy. As long as it helps find the kid, I'll pay.

"But please, don't do anything that could harm anyone else."

His words instantly won him favor with many neighbors.

"Dr. Lynch, you're such a good person."

"See that, Sophia? Dr. Lynch is offering you a better solution. What more do you want?"

Would he really be this generous if he knew I didn't have leverage over him?

I ignored him and spoke to my computer instead. "Sam, are you ready on your end?"

From the speakers came Sam's tired but steady voice. "All set. Just say when."

He was in Alvoria, across the vast ocean. He was my backup, my last card to play.

The countdown entered its final minute.

In the group, everyone held their breath, waiting to see what shocking scandal would be exposed about Dr. Lynch. He was so nervous that he spammed the group with countless begging emojis.

Time was up. I didn't send any links, just a message. "@2101DocLynch, your wife just threw all three of your laptops and hard drives out of the window."

A chorus of gasps rose from downstairs, followed by the thunderous crash of falling objects. Then came the hysterical roar from Dr. Lunch's apartment, Unit 2101.

I closed the residents' group chat. I knew he was finished. The records of all the illegal organ transplants he had conducted over the years were enough to put him behind bars for life.

Finally, Officer Holt called. His voice was full of shock and disbelief. "Hey, Sophia. We, uh… We found the cleaning lady at home. She had hanged herself."