“Marguerite,” he whispers as he fastens a breathing mask over my nose and mouth. “You’re safe, all right? You’re safe. Just breathe in and out, as deeply as you can.” All I can do is nod, and breathe.

Within two inhalations, I feel slightly better. Which is to say—I feel like crap, but no longer like I might be on the verge of passing out. “What is this stuff?”

“Don’t talk,” Paul says as he unfolds a shiny insulating blanket and covers me with it, tucking it around my shoulders, my legs. “You’re breathing a special gas designed to counteract pressure sickness. Very advanced. Invented by the brilliant oceanographer Dr. Sophia Kovalenka.”

Of course Mom turned out to be as much of a genius in oceanography as she was in physics. Of course. I can’t help smiling beneath the mask.

Paul sits on the wet floor by me, close enough to lift my head so that it rests against his knee. His hands warm me, rubbing my cold arms and legs, even as he bends and kisses my forehead.

“I wasn’t sure it was you,” he murmurs. “It could have been Theo in the pod—and I thought, if he left her down there, if he hurt her, stranded her—”

“No. He’s the one who’s stranded.” I look up at him as best I can with the silver mask over my face. “I took Theo’s Firebird. That means Dad can go home.”

“My God.” Then Paul bends over me, cradles me in his arms, as if he’s sheltering me from the whole world. I close my eyes, and despite everything, I think I’ve never felt so safe.

We rise through the water until it once again turns blue around us, and the breathing mask is no longer necessary. Paul only stops looking after me to dock his sub—one of the bigger, long-distance models that only travel with the largest science vessels.

“We get to go home,” I whisper. Moments ago I was exhausted and terrified; now I’m warm and safe in Paul’s arms. I could almost fall asleep right here in his lap, pillowing my head against his strong chest. His muscles flex as he works the directional controls; I love that he’s piloting the sub without letting go of me. “We won.”

“The battle. Not the war.”

“I know Triad will come after me again. I realize that. And they think I’m theirs to manipulate.” I’m vulnerable to them; as long as there are people in the world I love, that will be true. But vulnerable isn’t the same as helpless. “They’re going to learn better.”

Paul smiles. “When they went after you—Triad didn’t know what they were getting into.”

He turns his attention back to the controls as we complete docking. The clamps settle around his sub with a solid, metallic clang, and I hear the whirring sound of the station’s airlock coupling with ours. Paul puts one hand under my knees and stands with me in his arms, carrying me to the portal.

When the door swooshes open, Josie is standing on the other side to check in the latest refugees. She startles as she sees me. “Marguerite?”

“We wrecked,” I say. “Theo’s still out there. I swam up the first couple hundred feet; Paul picked me up from there.”

“Holy crap. You crashed the submersible?” Josie puts her hands on her hips. “And exactly how many guys are showing up to visit you today?”

“I think she’s a little out of it,” Paul says to Josie, as he gently settles me back on my feet. “At any rate, she could use something warm to drink and a lot of rest. And I know Marguerite wants to see her father.”

I say, “I can hear you, you know.” But Paul might not be wrong about my being out of it. I’m overwhelmed physically, emotionally, you name it. Right now I only want to curl back into Paul’s arms.

I take Josie’s hand and let her help me over the step. She guides me to one of the benches as she says, “Aren’t you coming?”

“No,” Paul replies.

“Paul?” I look back at him. He stands there in his own sub, his T-shirt and slacks striped with water, the Firebird hanging around his neck. He looks at me as if he’s drinking me in, as if he’s trying to memorize me. “What are you doing?”

“The storm’s blowing in hard. Theo’s in a broken submersible hanging over the edge of the trench. I can’t leave him out there.”

Josie turns on me. “Wait, what? You wrecked in the trench?”

I ignore this. “If it’s dangerous for him, it’s dangerous for you. And he’s the one who started it.”

“The Theo who spied on us started it,” Paul agrees. “But the Theo from this dimension never hurt us. He doesn’t deserve to die for someone else’s sins. And . . . he’s Theo.”

He’s right—so right it shames me. “I shouldn’t have stranded him down there.”

“You stranded that guy? On purpose?” By now Josie is beside herself.

Paul takes one step toward me, his gray eyes intense. “You did what you had to do, to save your father and yourself. Don’t blame yourself for a situation someone else put you in. But I have to rescue Theo if I can.”

“You just had to ditch me one more time on this trip, huh?”

“Marguerite—”

But I can’t even deal any longer. “Go, and come back in one piece, or I swear to God I will kick your ass.”

Paul touches my face—his thumb against my still-wet lips, like a kiss—then steps back into his sub. His hand thumps a panel on the wall, and the doors slide shut again.