At the end of an hour, I’d covered about a hundred square feet. I’d found three rusty cans, a corroded watch, shards of china with edges worn smooth by the water and a crystal champagne goblet miraculously whole. I’d also found a number of pieces of wood so logged by water they’d sunk to the bottom.

It was seven o’clock and completely dark now in the upper world. My shoulders ached from pushing through the weeds, my nose was running and I was feeling sorrier for myself than ever. I put the goblet on the edge of the pond next to the china, tied off my line, and dove again.

At seven-thirty, I’d added more cans, some forks and spoons, more china shards and a woman’s ring to my trove. The ring had been there for some time, judging by the amount of dirt on it, but it looked as though it might have impressive stones in it. I zipped it into a pocket of the wetsuit.

At eight, when I was so cold and discouraged I wanted to quit, I found a pocket organizer. I surfaced and stared at it. I was numb, unable to summon any excitement, but I knew it had to be either Marc’s or his murderer’s-beneath the muck of dirty water and plant detritus, the grain on the brown leather was still visible. My hands were too thick with cold to try to open it here. I hoisted myself out far enough to zip it into my pocket next to the ring.

I’d covered most of the pool by then. I was tempted to call it quits, but I only had one more section to do. If I didn’t search it, I’d lie awake all night imagining the vital piece of evidence I’d overlooked. I sucked cold air into my damp lungs for a few minutes, then slid back into the water.

Nothing else was there except more wood. One piece felt as though it might actually be an artifact, not just a dead branch. I brought it to the surface with me. Pushing myself thankfully free of the murk, I walked around the pond undoing my lengths of twine, looping it around my shoulder. My legs were wobbly from two hours of diving and kicking.

Before I could start gathering up my trove of china and glass, I heard footsteps whicking across the lawn. I gripped the breathing tube between my teeth and slid into the pond, remembering at the last second to switch off my headlamp.

Water amplifies sound. The feet-Catherine Bayard’s? Ruth Lantner’s?sounded as though they were pounding past in hobnailed boots. I waited a long minute, giving her time to clear the pond and head up the lawn to the house. As I was starting to climb out again, I heard another set of feet crunching along the brick walk next to me. I dropped back under water. The steps stopped. A light shone across the pond’s surface.

My heart stood still. I held my breath while the light played through the tangle of reeds, lily pads, dead fish. Surely my breathing tube didn’t stand out in that mess. After a moment, the light swept away; the steps moved on.