His breath condensed in the dampness before it dispersed in the unrelenting darkness. Jason Crowley never knew darkness could be so total until he descended to a place untouched by the light of day. Never seen by the eyes of man.

The path into the depths of Krubera Cave through pits, cascades, and pitches brought new meaning to tight quarters. Never one easy to scare, Jason found the suffocating darkness and narrow passages with thousands of feet of rock above them difficult to endure.

He adjusted the lamp on his helmet and turned from the shoreline at his feet to crouch back toward camp a few meters higher than the calm black water. Jason craned his neck so the beam of light illuminated the looming stalactites. Each sharp point dripped moisture upon the scraggily ground.

Rocks and dirt never touched by anything.

He crawled inside the closest insulated tent and found Peter Holt fiddling with the communications array.

Peter glanced his way and smiled. “Just in time.”

Jason sat next to him and noticed Peter’s hand trembling. He’d known him for twenty years and had never seen him nervous. Peter the Brave had been to the top of the world twice, unaided by oxygen. He survived a month in the Amazon alone and hiked across Antarctica on a dare. He’d never done nervous.

Peter said, “We’re about to connect to the surface.” He reached over and clapped Jason on the shoulder. His massive hand squeezed with strength gained by a lifetime of risks. “We’ve succeeded. We are where no man has gone before. Success, Jason!”

“I’m happy for you, Peter.”

Peter shook his head. “Be happy for all of us—we succeed together.”

The crackle of static filled the tent before they patched through Midway and heard Howard Taylor’s excited voice. “Hello down there. Can you hear us, Peter?”

Peter grinned as he depressed the talk button. “We sure can, Howie. I’m in such a good mood I don’t even mind talking to you!”

Jason laughed at the joke. Howard said, “Best we could get you on short notice, boss. What’s the latest down there?”

Peter pumped his fist. “We’ve done it, Howie. Tell everyone! Tell the whole fucking world it has a new bottom.”

They heard jubilant celebration over the speaker. Howard said, “That’s incredible news, Peter. How deep are we talking?”

“A little over seventy-two hundred feet,” Peter said. “Fuck, let’s be precise, Guinness will want to know. Seventy-two-sixty-four.”

“Amazing, Peter. What’s it look like down there?”

Peter winked at Jason. “Black as shit. Our battery supply better hold out.”

Howard asked, “Do you think you’ll go deeper?”

“I doubt it. From here, there’s a sump blocking our path and we haven’t enough supplies remaining to explore it. We’re spending the night at depth here, maybe tomorrow as well. What’s it look like up top?”

More static crackled over the line before Howard’s voice broke through. “A storm is closing in, latest tracking has it reaching us in three days. Radar shows it’s a powerful system, you might not want to be down there when it arrives, who knows what cave systems will flood.”

“Keep us posted. We’ll let you know the plan at morning check. Do me a favor, though, guys.”

“Anything, Peter. What do you need?”

Peter’s smile shone through the gloom. “Save me some chardonnay and sunshine. I’m missing both something fierce.”

Rushed footsteps and raised voices passed by outside the tent. Jason crawled out to investigate, followed close behind by Peter. The beam of Jason’s headlamp cut a swath through the darkness down to the placid water. Peter pushed past him to follow the commotion. Jason’s light bounced with each step as he hurried after him.

He followed Peter around a massive stalagmite and down a rock-strewn slope. The footing was dangerous with so many loose pebbles, and Jason slipped twice before reaching the rest of the team huddled together on the shoreline. Their headlamps cast a ghostly pallor over the cavern.

Peter asked, “What’s going on?”

“It’s Woz,” Dmitry said. “She started shouting she’d found something.”

“Why would Maja be down here alone?”

“An excellent question, Jason,” Dmitry said. The timbre in his voice gained everyone’s attention and calmed the undercurrent of murmured voices. “Care to answer him, Maja? You know the protocol—no solo exploring. What were you thinking?”

“Easy, Dmitry,” Peter said.

“Easy nothing,” Dmitry said. “I’m in charge of safety. The protocols put in place are to be followed to the letter. We’re at depth here, one fucking mistake and we all pay the price.”

Jason squeezed past the assemblage of bodies to go to Maja’s side. She was white as a ghost. He touched her elbow and asked, “Are you okay, Woz? What is it?”

A faraway look clouded her eyes. “We’re wrong,” she said.

“About what?” Jason asked.

“We’re not the first people to be standing here.”

“Bullshit, Woz,” Peter scoffed. “If anyone had made it this deep we’d know about it.”

“Not if it wasn’t recent.”

“What’s with the cryptic act, Woz?” Fatima Aydin asked. “If you have something to say, say it.”

Jason watched Maja Wozniak stiffen. Her eyes narrowed. She cast her light on the far wall so the beam shone just above the water’s surface. “It would be better if I showed you.”

Jason heard the group gasp when they saw the unnatural etching carved into the rock. He stammered, “Is that . . . ?”

“Omega,” Maja said. “Someone carved the last letter of the Greek alphabet into the rock.” She looked at Peter. “Someone had to be here before us to do that.”

“Come on,” Peter said, “water could’ve done that.”

Jason avoided Peter’s pleading gaze.

“What does this mean?” Fatima asked.

“It means we have done nothing that hasn’t been done before,” Maja answered.

“Wait a minute.” Peter’s voice rose as he struggled to hold on to his accomplishment. He pointed across the water. “This proves nothing. We don’t know how that got there, or even what it is.” His eyes searched the surrounding faces. “Just because it looks like a Greek letter, doesn’t mean it is. Remember the face on Mars?”

“Are you suggesting an optical illusion?” Fatima shook her head. “At this distance?”

“Then we go deeper!” Peter shouted.

“We can’t find a way through the sump,” Dmitry pointed out. “And our supply of oxygen is running too low for exploratory dives to search for a way through that may not even be there. We need to go back.”

Peter whirled on him. Wild abandon flashed in his eyes. “Fucking find a way!” He stared at the group for a moment, then pushed his way through his teammates.

Dmitry moved to follow him, but Jason held him back. “Let him cool off.” The group dispersed. Jason gazed across the water at the chiseled mark.

“What is it?” Fatima asked.

“Hmm,” Jason answered, “Omega also means the end.” He walked past her. “But the end of what?”

Jason removed his helmet and set the light between them. It cast shadows on their faces. He stretched his legs out to the water’s edge.

Peter sighed after a moment. “You don’t need to check up on me.”

Jason shrugged. “What makes you think I am? Not a lot of legroom in those tents.” Silence stretched between them. In the quiet, Jason listened to moisture drip from stalactites and splash amongst the loose rocks. “It’s understandable to be disappointed, Peter.”

Peter snorted. “Disappointed, what do you know of disappointment?”

“Peter—”

“No,” he interrupted, “I’ll tell you about disappointment. My whole life I’ve harbored one ambition. To leave my mark upon this world. Everything I’ve done so far . . . summiting Everest, trekking the Amazon, journeying to both poles . . . it’s all been following in the footsteps of men greater than myself. Following a path already laid out.”

Peter kicked at the pebbles under his feet. “But this here . . . this was mine. No one had ever done this. No one had ever gone this deep into the earth. This would be my mark. Can you imagine how it feels to achieve a life’s ambition, and then minutes later, have it stripped from you, rendered meaningless? That, Jason, is the essence of disappointment—the purest definition of failure.”

“That’s harsh, Peter,” Jason said. “It’s all right to feel like this expedition is less than a complete success, but it’s a long way from being a failure. We’ve accomplished a lot. Our names—your name—will still adorn the record books.”

“With an asterisk, maybe,” Peter said. “I’ve been second place before, Jason, it’s just the first loser.” He whispered, “We need to go deeper.”

Water lapped at the shore and echoed in the space between them.

“Are you okay, Peter?” Jason shifted on the hard ground. “You understand I have to ask? The way you acted with the group, the way you’re talking now, the others will take their cue from you as leader of this expedition. We walk the razor’s edge down here, and we need to rely on each other if we’re to make it back alive. You need a clear head to guide us back up top. Can we count on you?”

Peter gazed at him. Darkness shaded his eyes and made him appear devoid of feeling. “I’m fine.” Peter stood and patted Jason’s knee. “I may be down now, but I’m not out. I’ll be there to the end—you can count on me.”

His tent flap unzipped, waking Jason from a fitful slumber. Dmitry stuck his bullet-shaped head inside and said, “Follow me.” His tone left no room for argument.

Jason threw the sleeping bag off and crawled out of the tent. He turned his headlamp on and did his best to stretch the sleep from his weary bones. His eyes fell upon Dmitry as he unzipped the door to Peter’s tent.

“Wake up, Peter,” Dmitry said. “We have a serious problem.”

Peter ducked his head out of his tent and asked, “What’s happened?”

Dmitry ground his teeth. “Woz is missing, along with diving gear and an oxygen tank.” He turned his head toward the water. “She’s gone into the sump.”

Peter climbed out of his tent. He looked at Jason, then back to Dmitry. “Not by my orders.”

Dmitry spread his arms apart. “You made a big deal yesterday of going deeper, now this.”

“Woz knows better than that,” Peter said. “And I don’t appreciate your insinuation, Dmitry.”

Dmitry stepped closer to Peter. Their chests bumped and Dmitry said, “I warned you at Gambit we used too much oxygen getting there. We needed to turn back. You insisted on going another two hundred meters to set the record.”

Dmitry stabbed a finger against Peter’s chest. “I agreed if only that far. I told you any farther and we wouldn’t have enough oxygen to get back through the sump at Kvtochia. Now Woz is missing with a tank.”

“We can have more tanks brought down. It just means waiting a little longer before returning to the surface.”

Dmitry shook his head. “There aren’t enough people at midway to carry down the number of tanks we need, considering their needs as well. Another thing I warned you about. A storm is blowing in up top and the rivers will flood down here. We can’t afford to wait a little longer.”

Peter stiffened his posture. Jason noticed he still fell short of the burly Russian’s stature. “I know you get paid to worry, Dmitry, but I’m the one paying you,” Peter pushed back. “Mind your tone.”

Dmitry said, “I’m not paid to worry, I’m paid to get you all back to the surface—alive.”

Jason stepped forward to separate them. “This isn’t helping.”

Dmitry brushed Jason’s hand away from his chest. His tone still biting, Dmitry asked, “How did she secure a tank on her own?”

Jason answered, “We don’t watch them—there’s an implied trust.”

Dmitry lowered his eyebrows and turned away. Peter asked, “Do we know how long she’s been gone?”

Dmitry pointed to the glow of headlamps close to the shoreline. He lumbered around a stalagmite and headed toward the water. Jason and Peter followed on his heels. Dmitry said, “Fatima discovered the missing tank around midnight, so she’s been gone at least two hours.”

“We need to go after her,” Peter insisted. “She could be in trouble.”

Dmitry whirled on him. His meaty hands stopped Peter in his tracks and made Jason jump backward a step. “Have you not listened at all? We can’t afford to go after her—we don’t have enough oxygen to get us all back to the surface. I won’t waste anymore.” His voice rose so all those gathered around the sump could hear. “I told you all—one mistake is all it takes down here. Woz may have killed us all.”

Peter knocked the Russian’s hands away. “I won’t leave a teammate behind to die.”

“Either she dies, or we all die,” Dmitry said. “She made her choice, now you need to make yours.”

Moisture dripped into the sump. Jason stared across the dark water, his light illuminating ripples along the surface.

Peter said, “Grab the dive gear, Jason. We’re going after Woz.”

“You’re killing everyone here!” Dmitry shouted.

“She isn’t in the sump,” Jason whispered.

Peter looked at him and said, “What?”

Jason turned from the water. “Look at the surface, Peter. There are no bubbles. Either Woz found a way through the sump or . . . she’s no longer breathing.”

Dmitry said, “You want to risk our lives further for a dead woman? Do so, and we’ll join her soon enough.”

Jason watched Peter stare down Dmitry before his hard gaze turned to him. “Get the gear ready. We don’t know she’s dead.” His eyes returned to Dmitry. “And I’m not giving up on her.”

The opening stood only three feet wide near the bottom of the sump. On approach, Peter held up two fingers and pointed them over top of his left wrist. Even in the murky depths, Jason understood the sign meant Peter would lead.

With one last look around, Jason followed him through the narrow restriction. The passage redefined tight. A rush of claustrophobia surged within him as soon as the opening vanished from sight.

Bubbles from his rebreather floated past his goggles as Jason struggled to shift his left shoulder out of the way of himself. He couldn’t see behind him, the tight space kept his eyes pinned forward. He tried to control his panic.

Jason felt the walls close in on him. Peter’s flippers flashed at the edge of his lamp’s range. The thought of being alone down here propelled him forward. He steadied his breathing as more bubbles rushed past him.

I’m fine. I’m fine. I’m fine. He repeated the mantra inside his head, over and over again.

Jason felt water drip in his eyes and blinked the sweat away. His mouth dried out and his hands shook. He swam forward and stopped. His feet continued to kick but he no longer moved. Ahead of him, Peter slipped from view.

Jason’s eyes widened with the realization something held him in place. It could be my tank, or wetsuit, or even the oxygen hose. If I force the issue and it’s the hose . . .

A storm of bubbles drifted past his eyes—one less breath he had to take.

Jason wiggled his hips and pressed his hands against the passage floor. He was stuck. He thought about sliding back the way he came, but there was no guarantee he wouldn’t rip open his oxygen hose. And going back also meant swimming backwards and blind.

Damn. He closed his eyes a moment, and the terror gripped him. Jason clamped down harder on his rebreather. Is this what happened to Maja? Did she suffocate alone in the dark?

Needing to believe it wasn’t his oxygen line snagged on something, Jason moved his shoulder into the rock. It dug into his side. His teeth bit down harder on the rebreather. Breaking free, he drifted with the current again.

Relief flooded him until his leg seized. My wetsuit!

Cold water shocked his exposed skin. Jason wanted to scream, but kept his teeth tight around his rebreather. I need to get through this passage before my leg numbs up to uselessness.

Swimming forward, his leg throbbed as the water numbed him faster than he hoped. More frantic bubbles floated past his goggles. He shone his light ahead and glimpsed Peter out of the depths. Jason rushed toward him, Peter’s legs kicking up silt from the floor and obscuring the view ahead.

Jason came up behind him and waited for Peter to continue through the restriction. As the minutes passed, Peter’s frantic kicking took on new meaning. He’s stuck! If he’s stuck, then so am I.

A thousand pinpricks stung Jason’s leg and clouded his mind. Bubbles joined the floating silt behind Peter. Jason worked his right arm forward and snagged one of Peter’s flippers. Peter stopped. In the narrow confines, they could not look at each other.

Jason angled his light underneath Peter, hoping it would illuminate where Peter was caught. Bubbles exploded from Jason’s rebreather as he screamed a muffled cry. His eyes wide, he pushed back from Peter—his light having revealed limbs slack in the water.

Maja.

Peter’s waist jerked free and tossed more sediment into the cloudy water. He vanished through the junction, and Jason hurried after him.

Jason contorted past the outcropping that snagged Peter. He swam down a tapered section for a short distance before squeezing through a final constriction and escaping the claustrophobic would-be grave. He floated for a long moment in what he felt was a massive cavern, then followed the stream of air bubbles toward the unknown.