“Nothing that’s stuck.” He’d dated as an on-duty cop and before.

He’d even fallen in love once or twice, but it was never the challenging kind of love that made him want to be a better version of himself, not the type that made it all worth the struggle and sacrifice.

To his mind, God gave every serious couple an empty box, and each person had to be prepared to put more in than they took out.

In some of his relationships, it had been him doing all the filling.

In others, he wasn’t sure the woman welcomed what he’d added.

“You don’t want to put down roots?” Kit’s tone was more curious than offended, and he took courage.

He ducked under a low spot to avoid a whack to the temple. “Opposite, actually. I do want to put down roots with the person God meant for me, deep roots that will last as long as I do.”

Several beats of silence followed. “How do you know God didn’t mean for you to be alone?”

She was really asking the question of herself, he knew. He took her hand, cold and soft, and held it firmly. “’Cuz I’m not built that way, and people are better together.”

She cocked her head at him, like a bird, thinking. Considering, maybe? His heart thudded faster. The air in the tunnel grew colder and stickier under his boots. Far away came a rumble and roar, and the tunnel shuddered around them.

He stepped forward, but there was suddenly no solid surface under his feet.

Kit cried out and grabbed his belt which kept him from falling outright, but he still plunged forward as the tunnel floor dropped. An ungraceful stagger step prevented a faceplant, but he landed in frigid water up to his ankles.

The water rushed in from somewhere, passed his shins, and surged to his knees. Kit snatched the baby from the carrier.

“We have to go back!” he shouted, but a roar swallowed his comment as a fissure appeared high in the wall, gushing water and vomiting stone.

Within seconds the fissure widened to a crevice that dislodged the stones around it, sending rock bombs raining down around them.

They could not retreat through the deadly hail.

They splashed ahead through the swirling water. Kit held Tot as high as she could. He wanted to take the baby, but he didn’t dare stop to make the transfer or they’d risk being struck by the falling stones. Icy waves slapped at them, and Kit surged on with Tot held level with her shoulders.

“Look! There. Right there!” she screamed. Unable to point, she gestured with her chin. His heart leapt. Through the thundering swirl, he realized they’d made it to the end of the tunnel.

Half swallowed up by the water was a ladder similar to the first, gleaming in the light of their headlamps. A metal plate shone at the top with the familiar bolts.

The exit. They’d actually reached it.

He splashed toward the ladder. A rock ledge about halfway up jutted out a few feet.

With no time to explain, he held out his arms and helped Kit and Tot from the rising water, settling them onto the ledge.

He heaved the soggy bags up next to them.

The flow was lapping only eighteen inches below their perch and steadily rising.

He grabbed the sledgehammer from his pack and charged up the iron rungs.

As soon as he was within reach, he started slamming the protruding bolts.

This time he’d have to knock off the underside and hope it would be enough to prize open the trapdoor.

One bolt sheared away immediately. Excellent.

Maybe the damp had corroded all four bolts.

He continued to bang, the rushing water and his own frantic breathing loud in his ears.

The second bolt clanged loose. He spared a glance down to see that Kit was crouched on the ledge, her shins swallowed up by the water, Tot clenched to her shoulder.

They had moments left before it would be too late.

The third bolt gave way, then the fourth.

Elated, he applied his shoulder to the metal plate.

It didn’t move.

He whacked each corner with the sledgehammer until he thought the impact would shatter his wrists. The plate inched up on one end, the feel of fresh air bathed his face. But the metal refused to give farther.

More. He needed to move it more. Again, he shoved against the metal and pushed until his bones were about to break.

“Cullen!” Kit yelled. “What is that?”

He paused, scanning wildly, sweat stinging his eyes. “I don’t see anything.”

“Listen.”

Listen? He caught it. An electronic chirp he couldn’t place at first.

“It’s your phone,” she said incredulously.

He blinked, lashes spangled with droplets. He yanked the phone out.

Below him, Kit raised the baby as the water crept higher. “Hurry, Cullen.”

“Gideon?” he shouted in his cell. “Stop talking! We’re in a flooded tunnel somewhere underground near the town of Twinfork.

I can’t talk or we’ll drown. I’ll keep the phone on.

Track us if you can.” He shoved the phone in his pocket, which muffled his brother’s oaths.

“And stop swearing! You promised Mom,” he roared as he slammed the sledgehammer again.

“We got two ladies present, you big galoot.”

A frantic glance told him Kit was inundated to her torso. Water began to toy with the edge of Tot’s socks. Once she was cold, hypothermia would set in. How would they warm her? Save her?

“She’s getting wet,” Kit called frantically.

Gideon’s muffled interrogation continued.

“You have the worst timing ever, Gideon!” Cullen hollered in time to his sledgehammer blows.

“Most...” Clang. “Annoying...” Clang.

Before he got to the next adjective, the gap widened a few inches more.

Cullen braced against the metal panel and strained, pushing and grunting.

Another inch, then another until one more sinew-snapping heave levered the metal plate clear.

Praising God, he shoved the barrier out of the way.

There was no time for delicacy. He bent, grabbed Kit around the waist, and half-guided, half-launched her and Tot up and out.

Kit banged her knee on the way and let out a cry of pain.

He followed with the gear, barely able to summon the strength to haul himself free.

On hands and knees, he blinked the water from his eyelashes, panting. It was dark, but less so than in the tunnel. Immediately he turned to take Tot from Kit’s trembling arms. The adjustment in his vision came gradually, and the baby swam into focus. “Tottie girl? Talk to me.”

While he jostled Tot, he became aware that they weren’t outside as he’d expected. Instead, they were inside the remains of what had been a wooden structure but was now a collection of rotting beams. Where was the town? Help? People? Some kind of shelter?

As he rocked the baby, he took in the surroundings.

The broken building sat at the edge of a sprawl of rusted junk, discarded washing machines, and car parts, gleaming dully in the glare of his headlamp.

They were in some sort of salvage yard. Every surface was covered by volcanic ash. No sign of human activity. Anywhere.

“Where are we?” Kit whispered.

He snapped out of his own shock as he fumbled in his pack and pulled out a silver emergency blanket, slipped a mask on Tot, and handed one to Kit. He peered closer at Tot.

“She’s not crying,” he said desperately, chafing Tot’s shivering body. They had to get somewhere warm fast. He wrapped the blanket around Tot and Kit before he got his night vision binoculars and surveyed.

“Past the junkyard about a mile or so there’s ... something.” He squinted, adjusting the lenses. “Sheds? No, trailers. I think it’s a trailer park.”

“A mile?” she said weakly.

But Cullen was focused on the phone he’d temporarily forgotten. “Gideon? Are you there?” He shook the device with increasing agitation. “Gideon?” He smacked the phone against his thigh. “Unbelievable. Lost him.”

She shook her head, and he realized she was struggling to speak.

They were all cold, so cold, and Tot was growing ever more still.

Kit tried to stand, but her injured knee gave out and she sat down hard.

Desperation felt like a river rushing through his veins. He bent at the waist. “Get on my back. Leave the gear. We’ll get to shelter and I’ll retrieve it later.”

She shook her head. “A mile’s too far and my knee’s not cooperating. I’m too heavy. Take Tot and come back for me.”

“We stay together, Kit, remember?” he said savagely. “Get on my back. Right now.”

Stiffly, she rose. He helped her stuff Tot inside her jacket before he crouched, and she climbed on.

His joints cracked and he struggled to get upright, but he did it, then staggered into motion as she clutched him around the neck.

She tried to aim her flashlight and help him avoid the obstacles.

He skirted piles of scrap until they emerged on a flat acre that must have been a lovely swatch of grass before the eruption.

The trailers seemed impossibly far away, tiny specs.

Don’t think about the distance. He wouldn’t fail. Couldn’t.

Each step, foot, yard was torture. He clomped onward, straining under the effort, past a fenced tarmac. At the far end was a blur of yellow.

“Cullen, stop.”

He couldn’t imagine why she wanted to stop, and he wasn’t sure he’d be able to continue on if he did. Momentum was the only thing keeping him in motion. “I don’t...”

But she dug her fingernails into his bicep to the point of pain.

He wiped his eyes and blinked. The faint yellow objects came into focus.

He wasn’t hallucinating.

“Buses,” she said. “School buses.”

And the gate was wide open.