Ellie kicked off her flip-flops and waded in, shivering happily at the chill of the water, which lapped around her knees. Her feet were frozen and her shoulders were warm, and she tipped her head back and closed her eyes, the events of the morning melting right off her.

“Three whole weeks,” Mom said as she joined her. “I’m going to miss this.”

Ellie didn’t need to ask what she meant. In her whole life, she’d never been away for longer than a few days, and Mom still assumed she’d be leaving soon for the poetry course on a scholarship that didn’t exist. But it wasn’t just that. This was her way of preparing herself for something much bigger. When she drove down to Boston and dropped Ellie off in that empty dorm room, it would be a preview of the next summer, when she would go off to college for real. This trip, this August: it was like the beginning of the end. It marked the start of their last year together.

And so she knew what it meant when Mom said three whole weeks, and she knew she should reach out across the surf and take her salty hand and say I know or I’ll miss this too. But some small and hardened piece of her heart kept her staring straight ahead at the invisible seam where the water met the sky.

“Three weeks isn’t that long,” she said finally, her words crisp and unforgiving.

Mom nodded, her eyes far away. She couldn’t have known what Ellie was really thinking: that three weeks was everything, and that she might not get that chance. She’d saved up $624.08 so far, and if she kept working at this pace, she’d have just under a thousand by August. But it wasn’t nearly enough, and the thought of saying no—of giving up this opportunity, or possibly even worse, asking for help—twisted at something inside her, made her feel miserable and hopeless and mean.

On the shore, Bagel was dashing back and forth, distraught at being left behind. When Ellie whistled, he plunged into the water with a little whine, keeping his nose high as he paddled toward them.

“Listen,” Mom said. “I know—”

But Ellie didn’t want to hear it; she took a deep lungful of air, then dove into the water, the slap of cold making her whole body vibrate, right down to her teeth. Through slitted eyes, she could see Bagel’s churning paws as he circled her in alarm, and she used her arms to push away the water, propelling herself forward several strokes before bursting back through to the surface.

To her surprise, Mom was at her side, shaking water out of her ear. “You can’t get rid of me that easily,” she said, and Ellie used one hand to wipe her eyes. The ground beneath them had sloped sharply away, and both of them were treading water, their feet busy beneath the surface.

“I wasn’t trying to,” she said, leaning back so that she was floating, the waves loud in her ears, the taste of salt on her lips.

“I know you’re still mad at me about Graham,” Mom said, and Ellie looked over at her. There were beads of water on her eyelashes, and her face looked very pale against the water. “You’ve been so quiet the last couple of weeks, and I know you must be upset, so I just wanted to say that I’m sorry.”

A wave lifted them gently, then lowered them again, and a few seagulls wheeled overhead. The sun off the water was uncomfortably bright, and Ellie squinted against the glare, unsure what to say. It was true that she was upset about Graham. She thought she’d been managing just fine from a distance. But seeing him today, being near him—it was like the pull of a magnet, powerful and inevitable. Even now, treading water under the high globe of the sun, she felt her equilibrium had disappeared. She’d walked out of the deli hours ago, but some essential part of her—something too important to lose—had been left behind.

“It’s okay,” Ellie told her eventually, her voice very small. “It’s not your fault.”

Mom let out a breath. Her arms were moving fast beneath the water, ghostly and pale. “He’ll be gone soon anyway,” she said. “It’ll get easier.”

Ellie opened her mouth to answer, but found she couldn’t speak. It was meant to make her feel better, she knew, but suddenly all she wanted to do was cry.

Mom’s words echoed in her head again: Three whole weeks. That was how much time had been wasted. That was how long it had been since she’d kissed Graham.

Three whole weeks.

Farther out on the water, an enormous yacht glided by, moving slowly against the blinding blue of the horizon, and Ellie thought of the newspaper clipping about her father, and the fact that he’d be in Kennebunkport this weekend with his family, probably on a yacht not unlike that one. She imagined he’d be staying in some sort of oceanfront mansion, flitting between elegant cocktail parties at night. He’d be spending the days out fishing with his two blue-eyed sons, who looked like catalog models but—given what Ellie had read about them—probably couldn’t get into the Harvard poetry program if they tried.

She swallowed hard, stung by the unfairness of it. It wasn’t just that she was working all these hours to scrape together money for a course she probably wouldn’t be able to go to anyway. It was that this was just the start of it. Next would be college: all those applications for loans, and Mom up late at night with a calculator, crunching the numbers. There were the ever-present worries about the house and the shop, the endless conversations about budgets and the drawers full of coupons, all things that wouldn’t be an issue if Paul Whitman were still in their lives.

When Graham had asked her how much money she still needed that night, the question had felt like a bullet. For him, a thousand dollars was probably what you tipped the hotel staff after a week at a resort. He probably earned that much in interest every single day. To him, it was pennies. It was peanuts. It was chump change.

But to her, it still seemed an impossible amount. It may as well have been ten thousand dollars. It may as well have been a million.

There was a lump in her throat as Ellie tore her eyes from the yacht. Bagel had started to paddle for the shore, and they both watched him go, the diamond of white on the back of his head bobbing as he swam.

“I think he’s got the right idea,” Mom said, giving a little kick in that direction. “I’m getting fried. Want to head in?”

Ellie dipped her chin in the water, shaking her head, then leaned back so that she was floating again, her hair fanning out all around her.

“Not yet,” she said. “I think I’ll meet you back later.”

“Okay,” Mom said, starting to swim in. “Don’t float away.”

The water lapped in Ellie’s ears as she bobbed there. Overhead, the seagulls were talking to one another across the great expanse of the sky, and the sun lowered itself toward the beach. She wasn’t sure how long she stayed out there, letting the waves carry her, her body light despite the heaviness of everything inside her.

After a while, she flipped herself over and began to swim back to shore, where she wrapped herself in a towel and sat down on her favorite rock—a flat slab that rose above the inlet like a miniature cliff—feeling the salt from the water dry on her face, the sun warm across her eyelids. She curled her toes around the edge of the rock and hugged her knees. Peering down, she was surprised to see a small round disk wedged between the stones, and when she reached for it, she felt a laugh bubble up in her throat.

It was a sand dollar. Not exactly the kind of dollar she needed.

She held it flat against her palm, examining the rounded edges, and the light tracings of a star in the middle. Out on the water, another expensive boat slid into view, and Ellie squinted out at it, the first, faintest pattern of an idea taking shape in her head. She sat up straighter, her waterlogged mind waking up again, working through the possibilities as she spun the sand dollar absently in her hands.