Their shoes crunch along the surface, and she hears Colin slip on the ice, and both guys laugh behind her. She doesn’t even turn around because she wants in. It’s different now that they’ve decided to go in together. Something heavy pulls inside her chest, a sudden tether to some unseen anchor underwater.

She turns and looks at him here and wonders if it’s true that she lived in the lake for so long. Did she see him? Is that the hunger that takes over every thought? Beneath the blue ice there’s something deeper, a space carved for them. It’s all she can do to not pull him down to the opening with her. Her hands are magnets and his skin is iron and their place together is just below the surface.

While Jay unrolls the foil blanket and unpacks his kit of supplies, Lucy strips down to her underwear, unwilling to waste a single second. Boots, pants, sweater, shirt form a rumpled pile at her feet. Her skin is startlingly white in the sun, iridescent and more opaque than she’s ever seen it.

She looks up at a surprised Colin, his eyes taking in every inch. He stutters a few sounds before fumbling with his own buttons to catch up.

“I’ve never seen you . . . like this,” he says, eyes bright, cheeks flushed.

Lucy glances at the opening to the water and then back at him. “On the count of three?”

They dive in, arms stretching out into the clear blue water. It presses against every inch of her, cold and silvery. When they dip under a fallen tree, a fluff of moss waves in their wake, releasing a million tiny bubbles to travel the surface. Lucy doesn’t know exactly where she’s going, but she’s pulled toward the deep end of the lake, under the shadows where the ice is thick and dark.

She feels Colin’s fingers brush the skin of her ankle, his hair on her thigh as he pushes to catch up and swim beside her. As she turns her head, she sees him trying to hold his breath. Behind them, his unconscious body floats to the surface.

“Let go,” she says as clearly as if they were on dry land. She takes his hand and pulls him closer. It’s warm in hers, solid and familiar. At the surface, Jay pulls Colin’s body out of the lake. “Jay’s got you out.”

He struggles for a moment, a look of fear passing through his wide eyes as he works to let go of the instinct to breathe. Tugging his arm, she leads him forward, where the deep blue slowly morphs darker and darker, turning into a tunnel of soft black.

“Luce,” Colin whispers from beside her. “Where are we?” “I don’t know exactly,” she says. And she doesn’t. Even though being back in the lake feels familiar, she realizes she’s never known what this world is. It’s not heaven or hell. It’s not a different universe.

Light shines above, and they both look to the whiteness over them and push up through the crystal-blue water until they break the surface on this strange, other side. It’s unlike anything Lucy has ever seen since her return, but the space is so familiar and tugs at something in the back of her mind, some instinct that she’s finding the world she retreats to when she vanishes.

There’s a brief flash of disappointment: Everything is the same—trees and boulders and the trail—but then Lucy realizes that it’s not at all like the shore they just left.

Instead, it’s a mirror image, a replica of the icy earth aboveground, but it’s so much more. More color, more light, more reflections on every surface. Entering this world feels like stepping into the center of a diamond.

Lucy and Colin climb out of the water onto a shore of sand so crystalline, it glimmers in the indirect sun filtered through the trees. Branches of amber, leaves of a silver green so bright Lucy has to blink away, let her eyes adjust.

Beside her, Colin is silent, and when she looks to him, she registers that he’s watching her reaction, waiting. “There was something different about that world, something perfect,” he’d said. He’s seen this every other time he’s been here, and it’s she who’s forgotten what it’s like, because, until now, she didn’t go under with him.

“You can see this?” she asks, looking up at a sky so blue it almost needs another name. It’s the lake reflected, an entire galaxy, a massive ocean in a single glimpse of sky.

He nods, taking her hand and pulling her toward the trail. But when she expects him to pull her in the direction of the shed, he surprises her, walking the other way, away from the field and the school buildings and deeper into the woods instead.

Beneath their feet, amber leaves crunch like splinters of precious stone. The snow is mesmerizing, winking back a hundred shades of blue reflected from the lake and sky. It’s like she can see every frozen, glittering crystal that blankets the ground and trees and hills beyond.

Lucy’s memories come back slowly, giving her mind time to adjust the same way her eyes adjusted to the light: first recover. And then see: see the world that must have been her home for the past ten years.

“It’s like a reflection,” she tells Colin, following his lead at a fork in the trail. “Everything up there is down here. Buildings and trees. Even the lake. Like Wonderland.” She points back at the water behind them, looking like a sapphire planted in a bed of quartz.

He must hear the awe in her voice because he stops, turning to face her. She shifts where she stands. “Except people. I mean, I think I’ve been alone, watching.”

His dark brows pull together, and he whispers, “I hate that.”

Not wanting to worry him, she adds, “I don’t think time passed the same way. I mean, I remember being here, but I don’t feel like I was sitting around, bored out of my mind for the past ten years.” His face relaxes, and she says, “I remember looking up, as if I could see everything through a glass. I think I was waiting. And I remember watching you.”

“Really?”

Nodding, Lucy takes his hand and leads him down the trail this time, feeling a pull to go forward, to keep moving. “I remember watching you on the hill during a winter social. You and Jay swung from a tree branch and jumped down onto the lake.”