A few feet from the bottom, there is a seam where two veins of rock come together. I run my hands along it and find the spot: a crevice about six inches wide. I reach my arm inside the crack, nearly to my shoulder. I pull out a small cloth satchel, then swim to the surface and catch my breath.

There’s an underwater shelf about a foot wide that I can balance on, where the arc of the island keeps me hidden from Claire. I untie the satchel and pull out a plastic sandwich bag, packed full of diamonds. Even through the plastic bag, they glint in the sunlight.

I take three diamonds about the size of peas and shove them down into the pocket of my cargo shorts. I think about it and then grab a couple smaller ones. The smaller they are, the easier to sell. I zip up the bag and hesitate again. I pull out several more—a combination of big ones and little ones.

“Okay,” I say aloud, “that’s enough.”

After I dive back under and replace the bag, I swim back toward shore. My arms and legs feel like they’re strapped to twenty-pound weights. My lungs strain to pull in enough air.

At the bank, I flop down on top of the sun-warmed granite and try to get my breathing under control. Claire sits next to me and gives me her brightest, most beautiful smile.

“You disappeared there for a minute,” she says. “What happened?”

“I was looking for sunken treasure,” I say.

“Find any?”

“Nope,” I say. “It was back here waiting for me all along.”

“Yeah?”

“Yeah,” I say, and I pull her down to kiss me.

When we’re finished making out for the third time today, we sit up and stare out at the lake, enjoying the view one last time. The sun is starting to sink in the sky, and I tell Claire that we probably ought to take the water taxi back.

“We don’t want to get caught out here in the dark,” I say. “Besides, I’m pooped from that swim.”

“That’s too bad,” she says, giving me a flirtatious smile. “I was hoping you’d still have some energy when we got back to town.”

“Oh,” I say. “Don’t worry. I’ll get my second wind.”

I begin to lace up my hiking shoes. My eyes wander back out to the lake. The island where the rest of the diamonds are hidden is easy to spot. The tree’s skeletal hand marks the location like an X on a treasure map. Or a grave marker.

I feel a twinge of fear, like I’m making the wrong choice. The smart thing would have been to tuck the whole bag into the pocket of my cargo shorts and then leave town first thing in the morning.

I realize now why I grabbed the extra diamonds from the bag.