I GRIP MY SPEARGUN tightly and ignore the blood pounding in my ears as we swim up into the entry bay. I expect a wave of shredders to ambush us, but the large, open chamber is empty. It’s illuminated with a diffused light that’s just right for our eyes. Two long gray corridors lead off the bay in opposite directions. Several powerful-looking tows and skimmers are moored along one side. An intimidating array of harpoons and spearguns hang on the wall above the skimmers.

:Whoa, those babies look like fun,: Thom says wistfully, gazing at the skimmers.

:If you could steal a couple of those, you could get away faster,: Tobin says to me.

:So could you guys, tonight.:

:Good point,: Penn says as we kick our way as quickly as we can down the gray corridor. With its solid floor and thick metal bulkheads, the corridor almost looks like a passageway on a ship.

I’m aware that we’re passing open doorways to workshops and storage bays that appear almost frighteningly clean and orderly. We stop just before a large metal rectangular access that leads to the level above us, and it’s lit with the same pale, diffused light.

I check my watch. We covered the distance in less than a minute. Penn grabs Spyfish and tucks it into his seapack.

:All right, the next patrol should be passing in sixty-five seconds,: Rohan says.

Ree uses her mirror to watch the level above us. My heart thuds against my ribs. What if the second-level shredder patrol is late? What if we’re still here when the first-level patrol arrives?

We’d be in for a nasty fight without dolphins to help us. I reach back to my quiver to make sure I still have my boomer.

:Hey, Nere,: Penn says, :I’m going to hide a jammer for you guys behind this bulkhead.:

:Thanks, Penn,: I say, hoping my mental voice sounds steadier than I feel.

:The second-level patrol is right on time. Get ready to move,: Rohan warns everyone.

Penn hides the jammer and darts back to join us. Thirty seconds after the shredders pass the access, we swim up through it to the second level. We head the same direction the shredders went. As we sprint down a long gray hall, I read the numbers on the doors.

:Bria says she’s in Sleeping Compartment 214,: Tobin tells us. :They lock her in there every night.:

We kick our way down the long, stark hallway, searching frantically for the right door.

:Here’s 214,: Rohan finally calls out and tries the handle. :It’s definitely locked,: he declares. :Thom, you’re up.:

Thom reaches into his seapack, takes out a small explosive device, and attaches it right above the door lock. Thom’s our demo expert, since he knows all about explosives from when he was a guerrilla fighter.

:Bria, you need to move back into a corner, on the same wall as the door,: I hear Tobin tell her. :We’re going to use a charge to blow the lock.:

:Okay,: she says. :We’re out of the way now.:

We? There’s someone else in there with her? Before I can ask Bria what she means, Thom sets the charge.

:Everyone, move back,: Thom warns us. :This sucker’s gonna fire in ten seconds.:

We all dive away from the door. I glance at my watch. The shredder patrol will be back here in less than three minutes.

There’s a flash of light, a dull thud, and Thom goes to check his handiwork.

:Think I got it,: he says and shoves against the door. It swings open easily. We let Tobin go through first, but I want to be second.

Bria is there, her hazel eyes wide with excitement. I’m relieved to see her bright smile. Tobin grabs her in a big hug. Still wondering about the “we” Bria mentioned, I glance around the small room uneasily. Hoping to pick up a stray thought, I listen hard but don’t sense anyone besides Tobin and Bria in the chamber.

I hug Bria, too. :Sweetling, I’m so happy to see you, but didn’t you say there was someone else in here?:

:Just Shadow,: Bria says. :You don’t need to worry about her, though. She wanted you to come.:

A girl materializes out of a shadowy corner. She has large, dark eyes and very pale skin. Her long black hair, moved by stray currents, twines about her face. I raise my speargun to cover her.

:I’m not going to stop you from taking Bria,: the girl says.

I stare at her suspiciously. :So…do you know where they’re keeping Robry? We’ve come for him, too.:

She hesitates. :You’ll never be able to reach him without getting caught. His room is too far inside the fortress. You should just take the little girl and go.:

I study her for a long moment. Should we trust her? I try to read her thoughts, but she has strong mental shields. :We can’t possibly leave Robry,: I say at last.

:You really do care about him, too, don’t you?: The black-haired girl eyes me curiously. She has a small octopus shaped like a flower tattooed on her right cheek.

:We all do,: I say. :He’s a part of our team.:

A wistful expression crosses her face, but it’s so fleeting, I think maybe I imagined it. I keep trying to probe her mind. She’s definitely hiding something, but I also sense she cares about Bria.

:Let’s make sure Bria gets away safely before you go after Robry.: The girl crosses to the door, but Rohan is blocking her way.

:The next shredder patrol is due here in two minutes,: Rohan says.

:We’ll never get to the deck access in time,: I reply.

:We’ll close the door and hope the shredders don’t notice the hole,: Rohan decides. :Everyone inside Bria’s room now!:

Our rescue team piles in, and Lena pulls the door shut. A large round portal sits along the outside wall and a hammock hangs in the corner. The small chamber is light gray, and the metal floor is a darker shade. I’m startled by a beautiful picture, painted on the inside wall, of a dolphin surrounded by flowing lines. It seems so out of place in the otherwise bare room.

Considering what Shadow just said about reaching Robry, I wonder if it’s time for our groups to separate.

:Ree, our squads should probably split up soon,: I purposely broadcast on a public send. :Shadow says they are keeping Robry deeper in the fortress. You, Penn, Tobin, and Lena head back out with Bria. The rest of us will go look for Robry. Hold up outside the fortress, and we’ll let you know if you should wait for us.:

Ree’s gaze flicks to Shadow and back to me. :All right,: she says after a brief pause.

:Then we should probably say good-bye now,: Shadow says to Bria.

:Thank you for everything, Shadow.: Bria swims across the room and wraps her arms around the older girl. :I’ll never forget you.:

I’m surprised when Shadow hugs her back. :Take care of yourself, little fish,: Shadow tells her with a sad smile. Then she stiffens, an accusing look on her face. :Someone in here is bleeding.:

:Crud, it’s me,: Lena says, staring down at her hand. :I guess I cut myself on the door just now.:

:Get that bandaged fast,: Shadow says flatly. :The mutates you call shredders are hypersensitive to the scent of blood. They’re even worse than real sharks.:

Tobin is already moving toward Lena and reaching for his med kit.

:Ree, Thom, help me hold this door shut,: Rohan orders, :in case the shredders do sense Lena’s blood. Everyone else, stay quiet. The shredder patrol should pass by any second now.:

He leans over and watches through the hole torn by Thom’s explosive. I hold my breath.

:They are passing us…they’re past us, and they didn’t hesitate,: he reports. :I think we’re good.:

I’m not the only one in the room who sighs with relief. Tobin’s already finished putting a small pressure bandage on Lena’s hand.

:Okay, we’ll see you to the deck access, and then we’ll go find Robry,: I tell Rohan.

Thom opens the damaged door and we start down the corridor, swimming swiftly. After fifty feet, Ree yells from the rear, :Those shredders turned around. They’re heading our way fast!:

:Load your boomers,: Rohan snaps.

:They must have smelled blood after we opened the door,: Kalli cries.

:Penn, hit your jammer now,: I order him.

:You got it,: he says, hitting a button on the jammer he has strapped on his belt. I look down the corridor, my throat tight. The shredders keep coming. The scent of blood must be too tempting.

:Nere and Ree, form a front line with me,: Rohan says coolly.

:I will protect Bria,: Shadow offers to Tobin as she moves in front of Bria.

I glance at her as I raise my speargun. Shadow doesn’t look very dangerous floating there with no visible weapon.

:They won’t get past me,: she promises.

Her confidence convinces me, but I can’t blame Tobin when he takes up a position right beside Shadow.

:Pick your targets,: Rohan says as the shredders close the distance with frightening speed.

:I’ll take the one on the left,: I say. :Ree, you take center; Rohan, you take the right.:

We fire at the same time. Three of our boomers strike the shredders’ heads. The darts explode with a flash and a dull thud, slowing the creatures’ onward rush. The two shredders behind them keep coming.

Ree, Rohan, and I dive to the side to give the others a clear field of fire, but the two unharmed shredders are on us. Thom and Kalli fire next. They hit the charging shredders on their torsos, but these mutates wear body armor that appears to limit the boomers’ impact. Frantically, I reload my speargun.

One shredder stops and twists around, distracted by its wounded companions. It starts tearing at the closest, jaws chomping convulsively. The other heads straight for Lena. She fires at his head, but the shredder is moving so quickly that she misses.

:Lena, watch out!: Thom cries.

He lunges between Lena and the charging shredder, ramming his empty speargun into the shredder’s mouth—right up to his hand. The shredder clamps its teeth around Thom’s wrist and shakes its head. Before I can fire, Lena darts past Thom and drives her dive knife deep into the shredder’s eye. The mutate finally stops moving.

I twist around. Its jaw partly blown away, one of the shredders is still attacking. It lunges at Rohan and claws his arm. Before I can shoot it, Ree moves in close and fires a dart deep into its brain.

All at once, the whole ugly fight is over, and mangled shredders sink to the floor. Lena pries open the jaw of the shredder that attacked Thom. Gingerly he pulls his bleeding wrist from its mouth.

Tobin is next to Thom in a heartbeat, checking out his wound.

:Whew, I was afraid that mutate nicked your artery, but you lucked out. I think it still did a number on some of your ligaments, though,: Tobin says, shaking his head as he bandages Thom’s wrist.

:Thank you so much,: Lena says to Thom, her face still white with shock. :In another moment, I think that monster would have torn me to pieces.:

:You showed that sucker, though,: Thom smiles at her through his pain.

:I’m afraid you’re too hurt to keep going on with us,: I tell Thom. :You’ve got to head back with the others now.:

:Rohan’s too hurt to continue, also,: Kalli says as she bandages his torn arm.

:Then I’ll stay and help you search for…Robry,: Ree says with a quick glance at Shadow.

:I will, too. Ree and I are the only alternates left,: Tobin declares.

:But Bria needs you,: I can’t help protesting. I know she’d be devastated if something happened to her big brother.

:I want him to stay and look out for you,: Bria tells me, looking pale but determined.

:How are you going to get past the shredders on the lower level with three hurt people?: Kalli asks Penn.

:That won’t be hard,: Shadow says coolly. :The shredders are always starving. We’ll distract them with a nice snack.:

I’m startled when she grabs the leg of a badly mangled shredder, pulls the creature toward the deck access, and leaves it near the opening.

:All of you,: Shadow tells us, :get on the far side and stay absolutely still. The shredders on the lower level will sense the blood from this one soon. When they charge up here and start feeding on it, you can slip past them.:

:Won’t someone notice they’ve turned on one another?: Penn asks.

Shadow shrugs. :It’s possible, and then they’ll send more shredders after you. But you might get lucky. When you reach the entry bay, take some of the skimmers.:

:Why are you helping us?: I ask, poised to use my telepathy to probe her mind as she answers me.

:I like Bria, and I want her safely away from here,: Shadow says, a fierce light in her eyes. :Once he knows she’s escaped, Kuron’s going to send some of us after her on our fastest skimmers. You’ll never stay ahead of them just using your dolphins, especially with some of you injured.:

Once again, I sense she’s hiding something, but her concern for Bria feels real.

:The lower shredder patrol should be passing by here in about a minute,: Lena reminds us.

Rohan meets my gaze. :I say we go for it. The way shredders react to blood, I don’t know how we’ll get past them without a fight.:

:’Kay,: I say. :Everyone, let’s get to the far side of that deck access—fast.:

Leaving the dead shredders behind us, we sprint over to the other side.

:Let’s put Bria and the wounded behind us,: Ree suggests. :Who has boomers left?:

Tobin and Penn raise their hands.

:You’re our front line,: I say. :Have your spearguns ready. Penn, how long until they pass beneath us?:

:Fifteen seconds.:

If we have another fight with the shredders, I doubt we’ll all survive this time.