They wandered farther, past the estuary, among yards of green, translucent seaweed and squiggly tubes that squished beneath their sneakers.

Look, Isabel said.

She picked a large piece of something from the surf; it looked like coral, or like the bone of a small elephant ear or wings, with roundish ends and two hooped handles on the bottom. Was it a sea creature that had washed ashore? A crown? Isabel held it with both hands to her face. Upside down it made a perfect mask; she peered through the two arched sockets in the bottom.

Look, ’Livia, it’s the merman’s mask!

She stuck it in front of her head, dripping, antlered, and swung from side to side, holding the bone to her face.

Olivia wasn’t moving anymore. She stood completely still, the horseshoe crab at her side.

Izzie, I think you should put that down.

Her voice was unusually quiet.

Isabel whirled around with the mask; a little cold seawater dripped on her cheek.

Olivia shouted: Isabel, put it down!

Isabel lowered the bone to her side.

What, I found it!

I know, Izzie, it’s important, come on.

She turned back toward the house, but Isabel wouldn’t follow. Olivia trudged toward her and yanked her hand.

Come on!

Isabel gripped the bone; she wasn’t going to give it up that easily. She was sure this was one of her sister’s ploys.

Back up the bluff, Laura had just scrubbed out the sink when she saw the girls through the kitchen window coming over the bluff, one marching after the other, the sun in their hair—Isabel’s gold, Olivia’s chestnut—Isabel swinging the orange bucket. Oh no, Laura thought, back so soon; they’d fought already, but so quickly? She wiped her forehead with an elbow. She was wearing rubber gloves. There was something about the way they walked, Olivia with her face set, that didn’t look right.

Outside, on the lawn, Laura Fallon recognized the bone immediately. It was so obviously a human pelvis, leached of color, ash white, that she jerked a hand involuntarily to her mouth.

Isabel! she screamed. Drop that thing. Now!

Isabel, shocked by the ferocity of her mother’s voice, her wide eyes, let the bone fall from her grip and exploded into tears.

What had she done wrong? She’d found the mask, after all; it was hers. So what if Olivia wanted it; if only her father was there!

Laura grabbed Isabel tightly in her arms, and Isabel burst afresh into tears.

I told her to leave it on the beach, Olivia remarked.

Laura smothered Isabel in her dress. She hadn’t meant to scream; she wished she had remained calm.

Honey, you did nothing wrong, she soothed.

Olivia scratched the back of her right leg with the toe of her left; her braid was in her mouth again.