“A store-bought cake is supposed to be symmetrical,” she said before inviting us inside.

We drank tea from mismatched mugs while she described the visitors.

The first was Grant Sloane.

The second was a woman with a folder who introduced herself only as a neighborhood safety coordinator.

Evelyn had written down the vehicle plate numbers because she kept a notebook of everyone who stopped by.

Her memory was better than mine, but the notebook mattered more.

One plate matched the SUV photographed outside my house when Nina collected samples.

The other belonged to a contractor registered to Atlas.

Evelyn showed us a photograph of her garden from a decade earlier.

Beyond the fence, a shallow concrete opening had been visible near the creek.

It was partly concealed by brush.

“Children used to dare each other to look in there,” she said.

“My husband boarded up the approach years ago because it wasn’t safe.”

“Did anyone ever inspect it?” I asked.

“A man from the old factory came before the big cleanup.”

She pointed to a note in her notebook.

“He told us it was a stormwater structure, but he didn’t have the paperwork.”

I showed her Peter’s photograph of the concrete lid.

Evelyn studied it and shook her head.

“That isn’t the same place.”

Then she touched the lower corner of my print.

“But I know this marker.”

She described a chipped stone and a bent iron stake near the original creek crossing.

The location placed the missing chamber farther downstream than Peter’s sketch suggested.

It also put the structure beneath a proposed access route on the Atlas map.

I understood why the developers wanted the corridor.

I still did not understand why someone would pour tracer material into my pool.

Evelyn listened to the story without interrupting.

When I finished, she made a quiet observation.

“Maybe they weren’t trying to poison your water,” she said.

“Maybe they wanted people to believe the problem was at your house instead of somewhere else.”

Hannah and I spent the following day checking claims against documents rather than repeating them to anyone who would listen.

We sent Evelyn’s notebook photographs to Detective Tran and made arrangements for her to give a recorded statement.

We also contacted a licensed surveyor named Nolan Beck, who agreed to inspect the boundary markers without entering the disputed drainage area.

Nolan arrived wearing muddy boots and carrying an equipment case that looked as old as my father.