“Are they reopening it?” I asked.

“They want to turn the land into a warehouse park,” Doris replied.

“The proposal is still being reviewed.”

She leaned closer.

“And they are desperate for a different route to the highway.”

I looked at the easement map again.

The strip along my wall led toward the drainage corridor.

Beyond the corridor, the old service road ran behind the Sterling plant.

A route through our backyards would avoid a narrow bridge and a disputed creek crossing.

The explanation made the paperwork intelligible.

It did not explain the blue substance in my pool.

Before I left, Doris asked whether I had met a man named Peter Kellan.

I had not.

“He used to supervise maintenance at Sterling,” she said.

“He’s been asking questions about the cleanup reports, and everybody keeps telling him to stop digging.”

She wrote his name on the back of my receipt.

“He isn’t easy to find, but he still visits the veterans’ breakfast at the church every other Saturday.”

I learned the results on Friday at ten minutes past noon.

Mara called while I was standing in my garage, staring at a new scratch on the lockbox that held the pool equipment keys.

“We have a preliminary identification,” she said.

“It’s not a commercial swimming pool treatment.”

“What is it?”

“A ceramic carrier particle with a blue fluorescent tag.”

I sat down on a wooden stool.

“Explain that in plain English.”

“Imagine a tiny bead made to travel with moving water and leave an identifiable signal when somebody collects it.”

“Like a tracer?”

“Yes, but this particular batch appears to include an older industrial marker.”

I pictured the silver container beneath Meredith’s towel.

“Would somebody put it in a pool by accident?”

“It would be an odd accident.”

“Is it dangerous?”

“The immediate tests haven’t identified an acute hazard from the amount we sampled, but that does not certify the water safe.”

She spoke slowly, separating uncertainty from fact.

“Keep the pool closed until we complete the analysis and your pool professional clears it.”

“Where did the particles come from?”

“We’re checking the manufacturing signature, and I want a second lab to confirm it.”

I asked why a manufacturer would add a signature to such a substance.

“To distinguish one testing project from another,” Mara replied.

“If someone uses it where it doesn’t belong, the batch record can sometimes tell us who received it.”

I felt my hand tighten on the phone.