Aileen slipped off her kitten heels and held them in her hands. She turned her deep brown eyes on Eureka; they were the same color as her son’s. She lowered her voice. “Have you noticed anything strange about him recently?”

If only Eureka could open up to Aileen, hear what she’d been going through, too. But Brooks came and stood between them, putting an arm around each of them. “My two favorite ladies,” he said. And then, before Eureka could register Aileen’s reaction, Brooks removed his arms and walked to the helm. “You ready to do this, Cuttlefish?”

I haven’t forgiven you, she wanted to say, though she had read all sixteen groveling text messages he’d sent this week, and the two letters he’d left in her locker. She was here because of Madame Blavatsky, because something told her that destiny mattered. Eureka was trying to replace her final image of Blavatsky dead in her studio with the memory of the woman at peace under the willow tree by the bayou, the one who’d seemed convinced there was good reason for Eureka to sail with Brooks today.

What you do once you’re there is up to you.

But then Eureka thought about Ander, who insisted Brooks was dangerous. The scar on Brooks’s forehead was half hidden under the shadow of his baseball cap. It looked like an ordinary scar, not some ancient hieroglyph—and for a moment Eureka felt crazy for thinking that the scar might be evidence of something sinister. She looked down at the thunderstone, flipping it over. The rings were barely visible in the sun. She’d been acting like a conspiracy theorist who’d spent too many days cooped up with only the Internet to talk to. She needed to relax and get some sun.

“Thanks for lunch,” Eureka said to Aileen, who’d been chatting with the twins from the gangplank. She stepped closer and lowered her voice so that Aileen alone could hear. “About Brooks.” She shrugged, attempting lightness. “Just boys, you know. I’m sure William will grow up to terrorize Rhoda someday.” She tousled her brother’s hair. “Means he loves you.”

Aileen looked out at the water again. “Children grow up so fast. I guess sometimes they forget to forgive us. Well”—she looked back at Eureka, forced a smile—“you kids have fun. And if there’s any weather, turn back right away.”

Brooks held out his arms and looked up at the sky, which was blue and immense and cloudless but for an innocent cotton puff in the east just underneath the sun. “What could possibly go wrong?”

The breeze rustling Eureka’s ponytail became bracing as Brooks started Ariel’s engine and steered away from the dock. The twins squealed, looking cute in their life jackets. They balled their hands into excited fists at the first jolt of the boat. The tide was soft and steady, the air perfectly briny. The shore was lined with cypress trees and family camps.

When Eureka rose from her bench to see if Brooks needed help, he waved for her to sit down. “Everything’s under control. You just relax.”

Though anyone else would say that Brooks was trying to make amends and that the bay today was serene—a sun-blasted sky making the waves glisten, the smallest shimmer of pale fog lazing on the distant horizon—Eureka was uneasy. She saw the sea and Brooks as capable of the same dark surprise: out of nowhere they could morph into knives and stab you in the heart.

She thought she’d hit the bottom at the Trejean party the other night, but since then Eureka had lost both The Book of Love and the only person who could help her understand it. Worse, she believed that the people who killed Madame Blavatsky were the same ones hunting her. She really could have used a friend—and yet she found it nearly impossible to smile at Brooks across the deck.

The deck was made of treated cedar, dimpled by a million dents from cocktail-partiers’ stilettos. Diana used to go to Aileen’s parties on this boat. Any of these marks could have been made by the single pair of high heels she’d owned. Eureka imagined using her mother’s dents to clone her back to life, to put her on the deck right now, dancing to no music in daylight. She imagined that the surface of her own heart probably looked like this deck. Love was a dance floor, where everyone you lost left a mark behind.

Bare feet slapped the deck as the twins ran around, shouting “Goodbye!” or “We’re sailing!” to every camp they passed. The sun warmed Eureka’s shoulders and reminded her to show her siblings a beautiful time. She wished Dad were here to see their faces. With her phone, she snapped a picture and texted it to him. Brooks grinned at her. She nodded back.

They glided past two men in mesh baseball caps fishing from an aluminum canoe. Brooks greeted each of them by name. They watched a crabbing boat coast by. The water was rich blue opal. It smelled like Eureka’s childhood, much of which had been spent on this boat with Brooks’s uncle Jack at the helm. Now Brooks was steering the ship with easy confidence. His brother, Seth, always said that Brooks was born to sail, that he wouldn’t be surprised if Brooks became an admiral in the navy or a tour guide in the Galápagos. Whatever kept Brooks on the water was likely what Brooks would do.

It wasn’t long before Ariel left behind the camp houses and trailers, rounding a bend to face broad, shallow Vermilion Bay.

Eureka gripped the whitewashed bench beneath her at the sight of the small man-made beach. She hadn’t been back since the day Brooks had almost drowned here—the day they had kissed. She felt a mix of nerves and embarrassment, and she couldn’t look at him. He was busy anyway, cutting the engine and hoisting the mainsail from the cockpit; then he raised the jib up the forestay.

He handed William and Claire the jib and asked them to tug the corners, making them feel they were helping to bring the sails aloft. They squealed when the crisp white sail slid up the mast, locked into place, and filled with wind.

The sails billowed, then grew taut with the strong eastern breeze. They started on a close haul course, at forty-five degrees to the wind, and then Brooks maneuvered the boat into a comfortable broad reach, easing the sails appropriately. Ariel was majestic with the wind at its back. Water split across its bow, sending smothers of foam splashing softly onto the deck. Black frigate birds swooped in grand circles overhead, keeping pace with the leeward glide of the sails. Flying fish soared above waves like shooting stars. Brooks let the kids stand with him at the helm as the boat clipped west past the bay.

Eureka brought juice boxes and two of Aileen’s sandwiches up from the galley for the twins. The kids chewed quietly, sharing a lounge chair in the shady corner of the deck. Eureka stood next to Brooks. The sun bore down on her shoulders and she squinted ahead at a long, flat stretch of low-lying land overgrown with pale green reeds in the distance.

“Still mad at me?” he asked.

She didn’t want to talk about it. She didn’t want to talk about anything that might scratch her brittle surface and expose every secret she held inside.

“Is that Marsh Island?” She knew it was. The barrier island kept the heavier waves from breaking in the bay. “We should stay to the north of it. Right?”

Brooks patted the broad wooden wheel. “You don’t think Ariel can handle the open seas?” His voice was playful, but his eyes had narrowed. “Or is it me you’re worried about?”

Eureka breathed in a gust of briny air, certain she could see whitecaps beyond the island. “It’s rough out there. It might be too much for the twins.”

“We want to go out far!” Claire shouted between gulps of grape juice.

“I do this all the time.” Brooks moved the wheel slightly east so they’d be able to slide around the edge of the approaching island.

“We didn’t go out that far in May.” It was the last time they’d sailed together. She remembered because she’d counted the four circles they’d made around the bay.

“Sure we did.” Brooks stared past her at the water. “You’ve got to admit your memory has become disorganized since—”

“Don’t do that,” Eureka snapped. She looked back in the direction they’d come. Gray clouds had joined the softer pink clouds near the horizon. She watched the sun slip behind one, its rays frisking the cloud’s dark coat. She wanted to turn back. “I don’t want to go out there, Brooks. This shouldn’t be a fight.”

The boat swayed and they stepped on each other’s feet. She closed her eyes and let the rocking slow her breathing.

“Let’s take it easy,” he said. “This is an important day.”

Her eyes flashed open. “Why?”

“Because I can’t have you mad at me. I messed up. I let your sadness scare me and I lashed out when I should have supported you. It doesn’t change how I feel. I’m here for you. Even if more bad things happen, even if you get sadder.”

Eureka shrugged his hands away. “Rhoda doesn’t know I brought the twins. If anything happens …”

She heard Rhoda’s voice: Don’t take any chances, Eureka.

Brooks rubbed his jaw, clearly annoyed. He cranked one of the levers on the mainsail. He was going past Marsh Island. “Don’t be paranoid,” he said harshly. “Life is one long surprise.”

“Some surprises can be avoided.”

“Everybody’s mother dies, Eureka.”

“That’s very supportive, thank you.”

“Look, maybe you’re special. Maybe nothing bad will ever happen to you or anyone you love again,” he said, which made Eureka laugh bitterly. “All I meant was I’m sorry. I broke your trust last week. I’m here to earn it back.”

He was waiting for her forgiveness, but she turned and gazed at the waves, which were the color of another pair of eyes. She thought about Ander asking her to trust him. She still didn’t know if she did. Could a dry thunderstone open a portal to trust as quickly as Brooks had closed one? Did it even matter? She hadn’t seen or heard from Ander since that rainy night’s experiment. She didn’t even know how to look for him.

“Eureka, please,” Brooks whispered. “Say you trust me.”

“You’re my oldest friend.” Her voice was rough. She didn’t look at him. “I trust that we’ll get over this.”

“Good.” She heard a smile in his voice.

The sky dimmed. The sun had gone behind a cloud shaped strangely like an eye. A beam of light shot through its center, illuminating a circle of sea in front of the boat. Somber clouds rolled toward them like smoke.

They had sailed past Marsh Island. The waves were rolling in quick succession. One rocked the boat so violently that Eureka stumbled. The kids rolled around on the deck, shrieking with laughter, not scared at all.

Glancing at the sky, Brooks helped Eureka up. “You were right. I guess we should turn back.”

She hadn’t expected that, but she agreed.

“Take the wheel?” He crossed the deck to tack the sails to turn the boat around. The blue sky had succumbed to advancing dark clouds. The wind grew fierce and the temperature dropped.

When Brooks returned to the wheel, Eureka covered the twins with beach towels. “Let’s go down to the galley.”