“No attack, just watching in case we have any surprises,” Gabriel said. He picked up a tank. “Listen up—we only get one shot here, so pay attention.”

It was hard to pay attention when it felt like championship Ping-Pong was taking place in your stomach, but drowning didn’t hold any appeal either, so I clenched my teeth and did my best to focus. The wet suit didn’t help matters, as it fit like a tight, thick second skin that I desperately wanted to claw off.

“We can make it almost all the way to the cenoté without being submerged,” Gabriel said. “But the last ten yards are a tunnel and we will have to swim it.”

“We’re going into an underwater tunnel?” Mason already looked green, and this news made him clutch his stomach.

Gabriel nodded. “And the tunnel narrows just before you can access the cenoté. When you hit that gap, you’ll have to take off your vest and tank and push them through.”

Nev laughed. “You’ve got to be kidding.”

Gabriel’s expression wasn’t a kidding one.

Mason leaned over the side of the boat and retched.

“You can’t fit through the opening wearing your tank,” Gabriel said. “But it will only take you a minute to push the tank and then yourself through. Don’t overthink it.”

“You’re assuming it’s just us down there,” I said. “What if we have to fight our way in? Did anyone tell you about the spider?”

“No spiders down there, preciosa,” Gabriel said. “I swam the tunnel twice already—it’s a clear passage. The Keepers are only watching the top.”

His smile was warm and reassuring, but I felt uneasy.

“Listen,” he continued. “I’m serious about not overthinking this dive. Below the surface, the mixture of nitrogen and oxygen in the tanks can play tricks on your mind. At worst, hallucinations, panic attacks—and if you start to freak, it will be hard to turn it off. Comprende?”

Mason wiped his mouth and nodded.

“Besides,” Adne added, “it’s a one-way trip. No use getting all worked up.”

“Thanks for the vote of confidence.” Ren gave her a weary smile.

She punched him on the arm. “Not that kind of one way. I just mean once Shay has Eydis, I’ll weave a door and we’ll be back to Inez in time for dinner.”

“Fish tacos?” Connor brightened.

Gabriel shrugged. “Likely.”

The trip along the coast took an hour, during which we skirted a dark and unfriendly limestone coastline. The jungle hung over the water, its vines appearing to writhe just above the swells. By the time Miguel lowered the anchor, everyone but the Searchers and Shay had been sick at least once. Apparently wolves can’t find their sea legs.

I rinsed my mouth out with salt water as Gabriel gave final instructions on scuba safety procedures. “Remember, if you get into trouble, the person with a functioning tank is in charge. That’s how buddy breathing works. Got it?”

We all gave him a thumbs-up.

Gabriel pointed to the tangle of jade leaves and thick branches. “That’s where we’re headed.”

I peered at the shore and could just make out a sliver of darkness cutting through the glistening green.

“I will wait here for an hour,” Miguel said as he settled into one of the seats. “In case any of the lobos can’t handle the dive. None of you seem to have sea legs.”

Mason threw him an unfriendly smile, taking a deep breath before he and Nev put on their masks and fins, placed their regulators in their mouths, and jumped into the water.

“You okay?” Shay held my tank while I slipped my arms into my buoyancy vest and secured the safety belts.

I nodded. Bile was sloshing in my stomach again. I didn’t think talking would help.

“You’ll do fine,” Ren added, handing me a mask.

“I’ve got this,” Shay said. “Get your own equipment on.”

“I can help her too,” Ren growled. “Back off.”

“Don’t start,” I said, swallowing hard. “And I don’t need help from either of you. Just get in the water.”

They were both still glaring at each other, so I jabbed them away with my elbows, closed my eyes, and did a back roll into the sea.

Other than the way my blood roared in my ears as I sank beneath the surface, my world had gone quiet. Nearly silent.

Slowly, I adjusted to my surroundings. I wasn’t quite floating, but I wasn’t sinking either. The air in the vest kept me buoyant while I gently kicked my fins. I equalized the pressure in my ears by holding my nose and applying a bit of pressure until they popped and cleared, just as Gabriel had promised. The fins propelled me forward much more quickly than I’d expected. An adrenaline spike sent shivers through my limbs. I twisted in the water, graceful, unencumbered by weight. Maybe wolves were dolphins in another life.

Mason and Nev had also gotten comfortable breathing underwater and were now chasing a sea turtle, circling it the way they would a rabbit. I giggled and bubbles spouted up around me.

Four booms, like miniature explosions, came from above. I looked up to see that Shay, Ren, Adne, and Connor had entered the water. One final boom signaled Gabriel’s arrival. He immediately took off toward the shoreline, moving through the water lithe as a sea lion, with only a quick wave to indicate that we should follow.

Having just gotten comfortable with my new underwater surroundings, I didn’t feel ready to leave the open sea for the confinement of the cave, but I didn’t have a choice.

The tunnel loomed ahead, an absolute darkness in contrast to the aquamarine sea we were leaving behind. As we approached the black maw carved in the shoreline, the surge of excitement I’d felt earlier gave way to gnawing anxiety.

Gabriel surfaced just inside the mouth of the cave and pulled off his mask. I looked past him, trying to judge the distance between the water’s surface and the cave’s ceiling. Four feet, maybe five, but my flashlight’s beam showed that the ceiling sloped down farther into an ever-narrowing tunnel.

“I’ve already placed a guideline in the corridor where we’ll be submerged,” Gabriel said. “If you start to lose your sense of direction, just focus on the line. And remember, don’t overthink it. Just breathe, clear your ears as you descend, and everything will be fine.”