Down the hall, a door slams. The girls and I tilt our heads to the side, listening intently. Reece looks at us strangely as I press a single finger to my lips. He might not hear anything, but someone is coming.

Footsteps travel down the hallway, towards Dr Wells' office. I hold my breath and count to ten, praying they won't find us. When the footsteps pass, I slip back into the corridor first, waiting for the footsteps to retreat.

We're close to making it out of here, and yet it feels like there's miles more to go. Every second feels long and drawn out in the silence, but my heart races faster in my chest. This is it, our last chance to attain our freedom once and for all, because if we're caught, we'll be better off dead.

When they finally round the corner, I spring from my spot. My arms and legs buzz, practically moving on their own as they sweep me along the corridor. I have never felt so alive before, so terrified; this must be how prey feel in the seconds leading up to death.

Reece takes off on a trot and I follow behind, unable to shake away the image of that girl. My eyes begin to blur and my breath comes in gasps as a sharp pain wiggles its way between my ribs. Dr. Wells has finally achieved what she wanted–a real life hybrid mermaid. If it wasn't for Reece and the girls coming to save me, that was going to be me.

I swallow hard. I'm so breathless and unraveled that I run into the back of Reece, who has suddenly stopped a few feet in front of me.

When I look up, I see why. At the bottom of the hallway, six guards stand in a line with their guns outstretched, staring back at us. They're not moving or speaking, but one has a radio positioned to his mouth, like he's awaiting an order.

For a moment, I wonder what lies they've been fed about us. What tales Marine World has spun in order to gain their allegiance. I just can't accept that these guards would be doing this if they knew the whole truth. I have to believe they've been as lied to as we have, or else all of the good I am trying to believe in means nothing at all: humanity means nothing at all.

We round the corner and sprint to the bottom of the corridor, making it to the exit door that sits between us and the tunnels. Reece pulls out his key card and presses it to the pad, ushering us inside.

"It's a one-way emergency door," he says, keeping the door half open with his foot. "Dr. Wells is in charge of the whole system. If we can use her voice recognition to override key card access, we can deactivate the door and stop them from following us through."

My heart pounds harder as his words sink in. This door is just like the one I'd encountered in the medical room, which had been too thick for voice activation to work from the other side; I know it will be the same now.

"One of us would have to stay behind to activate it," I say. "Sound doesn't travel through these doors, you have to be on the same side as the keypad. Which means whoever stays behind to deactivate the door won't be able to get back through."

Time stands still as the girls and I look at each other. Through the window in the door, I see the security guards round the corner, making their way towards us. I glance back at Reece, whose breathing is loud. I imagine his heart thumping wildly in his chest, as wildly as my own.

Without thinking, I pull him towards me and press my lips against his. He tastes warm and sweet, the same way he'd tasted that night after the supermarket. I'd been terrified then, and I'm terrified now, but not about this. Not about him. After everything we have been through these past few weeks, he is the only thing I'm sure about.

His mouth pushes back, desperate to taste my own before he remembers where we are. He pulls back, annoyed, and grabs my shoulders as he searches my eyes. "Don't even think about it," he says, shaking me gently. "We'll just let them follow us. We can still make it."

He moves his foot in a bid to shut the door, but I stop it from closing with my hand. A part of me wants to be selfish and risk it all just to spend one more moment with him, but I can't. Crystal and Jewel deserve a fighting chance. They deserve to experience love and happiness and all of the things I got to experience outside; they deserve to live.

"He's right," Crystal says, her voice harder than usual. "You don't need to do this. We'll make it."

I shake my head with a heaviness in my gut. I want to believe that we'll make it out of here, but logic tells me that's only a dream. Deactivating the emergency door at least buys them some time and gives them a fighting chance.

"If I don't, we're going to end up back in an aquarium," I say. "This way gives you a fighting chance."

I'm about to go, but Jewel turns to face me and grabs hold of my arm, her expression defiant. "Get going then," she says, her voice urgent. "I'll hold them off. You get that footage out and make Marine World pay."

My eyes widen when I realize what she's saying. "No," I say. "I can–"

She throws herself at me, wrapping her arms around my neck. "Don't be an idiot," she says, her breath warm against my ear, "and don't you dare forget me."

I pull away to look at her. She is over to the door before I can make a sound, pushing me out of the way before closing it shut behind her. I throw myself against it, standing on my tiptoes to see out of the door's window.

Jewel hunches over the speaker as she deactivates the door, and then she turns to the guards as they close in around her. I expect them to take her away somewhere, to put her into another experiment or test, but then one of the guards presses his gun to her temple and he pulls on the trigger.

The gun shot rings out and vibrates through my ears.

I scream as Jewel falls, motionless, her chest no longer rising and falling with her fiery signs of life.

Just like that, Jewel is gone.

I clamp my hand over my mouth and look up, barely able to see through the tears. Reece grabs my arm and yanks me away from the door, pulling me down the rest of the corridor.

The next few minutes feel like I'm trapped in a nightmare. I'm vaguely aware of my feet pounding concrete, of the sobs in my throat, of the pain in my gut, and then Reece is shouting for me to keep on going, but I drop to my knees. My lungs inhale, exhale, inhale, but it doesn't seem to be working; I can't seem breathe.

Reece grabs my arm again and Crystal grabs the other, pulling me up to my feet. I meet Crystal's gaze, expecting her to look just as broken as I feel, but it's not defeat in her eyes; it's defiance.