My night in confinement is cold and sleepless. I lie still against the mattress until a tray is delivered through the slot in the door. On the tray is a glass of apple juice, a bowl of oats, a spoon, and two white pills. I wait for the keeper to leave before dropping the pills into the toilet and flushing the chain.

They told us our stomachs are smaller than the average human, our portions controlled because we require less food. As I tuck into my porridge, I find myself thinking back to the guests, wondering what it must feel like to eat whatever they want.

At nine a.m, Trainer Valerie arrives for a practise session. She is quieter than usual, her large brown eyes noticably shadowed by circles. It should be Trainer Lucy here. Her absence unnerves me.

We run through my routine in silence. I perfect every twirl, losing myself to the routine. And it is not just me who comes alive in the water, it is Valerie, too. We swim side by side, her legs kicking wildly in rhythm with my tail, her fingers wrapped tenderly in mine.

For a moment, reality is forgotten. We are not trainer and mermaid, both tuned to the beat of Marine World's drum. We are just two people seeking solace in the water.

Reece watches us from the corner, his expression dark and posture stiff. At one point during my routine, he is so close, I can't help but playfully splash him with my tail. He glares, and I flash an easy smile in return, relieved when Valerie smiles. Good. I need them to see me as a simple mermaid and not dangerous like Crystal.

"Okay, Aura," Valerie says. "I'm going to act as a guest this time."

She stands up from where she is perched on a rock, lowering herself into the water. Reece's hand twitches on top of his gun. Ignoring my racing heart, I take Valerie's hand and pull her through the water with me, making sure not to deviate from the routine. When the session is over, Reece and Valerie help to pull me from the water, unclipping my tail.

"All right," Valerie says. "Take a ten-minute break and then we'll head over to the Testing facility."

"When can I see her?" My tone is urgent. I've been useless at convincing them it was all just an accident, that Crystal hasn't done anything wrong. They wouldn't be watching me if everything were fine, and when Valerie gives me a long, anxious look, I know Crystal's not okay.

"Probably not for a long time," Valerie admits.

Probably not ever again.

Reece and I spend my break in silence, with me sitting near the ledge while he stares at the wall, pretending I don't exist. Rob walks in, nods to the both of us, and looks around the room. He beckons us over, so I slip on my nightgown and we follow him out.

He leads us through the underground tunnels. The tunnel is lit at long intervals, with only a handful of lamps guiding the way. It doesn't matter. I could do this journey with my eyes closed anyway.

Our footsteps sound loud and heavy in the silence. We pass three gray doors, then make a right. Then a left. We're heading to the Testing Facility.

I stop abruptly, and Reece smacks into me, hitting my back with his chest. His hands clamp down on my shoulders like a weight, keeping me steady. "Are you okay?" he asks.

I can't see him, but I can feel the warmth of his breath near my neck. "I'm fine."

Rob rests his card to the facility door and ushers us inside. The room is narrow, with concrete floors and dark gray walls. In the distance, several doctors gather around a large, glass box–the submersion tank.

"What is this place?" Reece asks.

Rob looks pleased. "They didn't brief you on this part, comrade? This, my friend, is the Testing facility."

Rob takes me by the arm and guides me toward the tank, positioning me in front of the door. Another routine–less familiar. More daunting. I slip off my nightgown, step inside, look ahead. But this time I don't focus on the wall or the doctors in coats, I focus on Reece. He is leant against the back wall with his arms folded, but his eyebrows are furrowed ever so slightly, betraying the easiness of his expression.

In front of me, one doctor stands out in particular: Dr. Megan Wells. Her blonde hair is scraped back in an efficient-looking bun, her clipboard held tightly between her manicured fingers. She seems to be in control of these tests. It's why I hate her.

Several minutes later, Asia arrives. My heart aches as she is led into one of the tanks. She catches my gaze and sticks out her tongue, pulling a brief smile from my lips.

"Test one, commencing," Dr. Wells says.

Water rises up from the bottom of the tank. It trickles between my toes, up the lengths of my calves and thighs, sending my heart racing. I take a deep breath when it reaches my lips, but keep my eyes open.

It's a test. They are pushing us to our limits, seeing how long we can hold our breath for before it all gets too much. It's easy for the first fifty minutes–it always is–but at fifty-five, I feel the tug in my lungs, the need to inhale. Asia raises her hands mid-air, creating a heart with her fingers. I make one back, forgetting for a moment the pain in my chest. At fifty-nine, my lungs are ready to burst at the seams. I tap on the glass, my signal to stop. Today they ignore me.

The timer on the far wall hits sixty-two. I start to panic, kicking and pounding like I'll break through the glass, even though it's impossible. Asia is still, her dark hair framing her face like a halo. I'm not sure if she is better at this or just better at pretending, but the calmness never leaves her expression.

Black dots start to cloud my vision, but the water is already draining. I collapse to the floor, tired, breathless, gasping for air. The door slides open. Dr. Wells smiles.

"Best time yet," she says. "Somebody get her towel." She walks off at once; her pointy, black heels clattering against the polished floors.

Slowly, and still panting for breath, I tilt my head to look at Reece, pushing away wet tendrils of hair to find his blue eyes on mine.