See you in Hell.

There was a bang, and smoke billowed from the top of the bag. Without thinking, Kat fell to the floor, dragging Enid down. The air roared, and she felt a blast of heat. The deck bucked and smacked her in the teeth. Burning splinters fell around her.

The automatic sprinkler systems went off; water hammered into the room. Kat lay for a moment, letting it splash over her face. Her ears hurt, and her lip bled. Enid lay across her legs. Painfully, she rolled over. She saw people screaming but couldn't hear them. The smell of scorched hair burned in her nose.

She pushed herself up onto her knees. Enid stirred.

Nothing remained where the table had been. The explosion had scattered broken furniture everywhere. Some of the pieces were burning. Three or four of the crewmen sported shrapnel wounds. One lay slumped in a pool of his own blood, obviously dead, a metal table leg punched through his chest. But something else had caught Enid's eye. She was saying something, but Kat's ears were still ringing from the explosion.

"What?" she said.

Desperately, Enid jabbed her finger at the wall. The explosion had weakened the skin of the observation dome. Spidery cracks ran up from the place where the table had been. As Kat watched, one of the cracks jumped a few centimetres in length, then a few more.

Enid screamed: "We're eight kilometres down!"

Before Kat could react, the ship's voice broke into her implant.

> Evacuate. Hull integrity compromised. Pressure seal in twenty seconds.

People started scrambling for the airlock doors that led to the elevators, and the safety of the ship's main hull. But Enid couldn't stand. She had a jagged sprig of steel skewering the muscle of her right calf.

> Pressure seal in ten seconds.

Kat grabbed her by the lapel of her jacket and, ignoring the pain of her own injuries, started dragging. She was halfway across the room from the airlock doors.

> Five seconds.

She heaved towards the threshold with all her strength. Hands were waiting there to help her, calling encouragement. They grabbed her coat as she got close, trying to pull her to safety.

> Four.

Her heel hit the lip of the airlock frame. Her hand jerked free from Enid's lapel, and she fell back into the waiting arms of her would-be rescuers. Enid shrieked.

"Kat, don't leave me!"

> Three.

Kat kicked and elbowed herself free of the hands holding her. She lunged desperately through the lock. On the other side, Enid reached for her. Their hands clasped.

> Two.

Kat pulled with all her might, but they were out of time. With a splintering crash, the glass wall shattered under the pressing weight of the ocean, and the room imploded.

VERTEBRAE BEACH GRID.

NEWS HEADLINES.

REVOLT ON LANCASTER.

Anti-government troops declare victory.

REPOPULATING THE OCEAN.

Terrestrial species to be introduced.

Fish farming to commence next year.

SHORTAGE OF PEP DRIVES PRICES TO ALL-TIME HIGH.

INTELLIGENT LIFE?.

Extinct indigenous shellfish may have used tools.

SOME LIKE IT HOT!.

New shipment of Italian chorizo sausage sparks fierce bidding war.

ARCH FAILURE?.

Fears of total network collapse.

TAX ON SEABED LIVING SPACE.

Critics claim poor will be hit hardest.

Tax on oxygen next?

SYLVIA ABDULOV REMEMBERED.

New statue to commemorate centenary of heroic rescue.

Former lover speaks out.

Disappearance still a mystery.

RATS!.

Every world has them. What makes them so successful?

HAGWOOD MISSING.

Poet fails to return from sabbatical on Djatt.

CHAPTER TWENTY-TWO.

TSUNAMI.

On the Dho Ark, the improvised human quarters were housed in a warren of caves and tunnels drilled into the rocky planetoid, especially to accommodate the expedition. Each of the team's one hundred members had their own alcove for sleeping: a narrow, coffin-like slot in a cavern wall, just big enough to contain a sleeping bag and air mattress, and into which they had to slide feet first. The caverns themselves served as shared living and study areas. The largest of all was the refectory, a circular room with a high dome-shaped ceiling. It was the only space big enough for the entire expedition to assemble, and therefore the venue Professor Harris had chosen for his presentation.

For five years, he had been working to frame the Dho's jumbled carvings into a coherent historical narrative. To accomplish this, he'd had to photograph, scan and analyse thousands of individual scenes-a process that the Dho themselves watched with tolerant amusement.

Now, clad in his threadbare tweed suit, he stood at one end of the room, in front of an unrolled soft screen. The rest of the expedition sat on chairs and tables, facing him. Toby Drake sat near the front, eager to hear his interpretation of Dho history. For five years, during breaks in his own studies of the second Gnarl at the heart of the Ark, he'd watched the old man mumble and mutter over image after image, and now he was as keen as anyone else to hear the conclusions his old teacher had finally drawn.

A handful of Acolytes stood patiently at the side of the room, hands folded in their drab habits. Behind them, a Dho observer stood as impassive and expressionless as a beetle, regarding proceedings with its shrivelled black eyes. Harris glared at it for a moment, returning its stare from beneath brows like wind-plucked storm clouds. Then he drew himself up to his full height and cleared his throat. Chatter died away. Behind him, the projection screen cleared to reveal his first image.

"Those of you who have spent any time in the halls will be familiar with this. As far as we can tell, it's one of the oldest carvings on the Ark, made during construction. Down here, you can see a group of Dho clustered around an instrument that we believe to be a telescope." Harris pointed to a group of horned stick figures at the bottom of the picture. Above them, two giant lights blazed like childishly drawn suns against a backdrop of smaller stars.

"We believe these two objects in the sky are novae. It appears that early in the Dho's history, two nearby stars exploded almost simultaneously. There are dozens of images of the event in the halls of this Ark, and judging from these related carvings we can see that the twin novae had a profound effect on Dho culture and religion. Almost overnight, their old gods were swept aside. They became scholars and astronomers, in an effort to comprehend what they were seeing. And finally, they understood enough about stellar evolution to realise something that startled them even more than the initial explosions."

Harris turned his hooded gaze on the Dho, as if waiting for it to confirm or deny his words, but the creature remained mute and immobile, its emotions unreadable. Irritated, he continued: "They call this picture The War In Heaven, and I believe that's exactly what it depicts. By piecing together hundreds of images, I am now certain that what the Dho found in the afterglow of the two explosions was more than simple coincidence. They stumbled on a war. Two races fighting in the depths of space, each with the power to destroy suns."

The audience stirred. Harris ignored them. He gestured at the screen and the image changed. This second carving was larger and far more intricate than the first, and pictured the diamond Ark under construction above the Dho's home world. Digging machines bored into the rock of the planetoid. Other machines extruded sheets of crystal.

"Fearing that they would become embroiled in this gigantic conflict, the Dho prepared to flee." Harris paused again. Toby saw sweat peppering the old man's forehead. "However, before they were ready, the sky fell quiet. Violence turned to silence. The fighting ceased."

The professor snapped his fingers at the screen and it flicked to a third image: an oncoming storm of billowing cloud.

He cleared his throat.

"We cannot be sure exactly what this cloud represents and our hosts have been most reluctant to expand on the matter." His eyes were on the unmoving Dho at the side of the room. "It may have been an expanding nebulae of hot gas left over from the stellar explosions, a dust cloud or maybe a weapon of some sort. All we know is that they were so afraid of it that they completed their Ark and abandoned their home planet."

Another click of the fingers and another slide appeared. Toby felt a mild thrill. This carving was the most familiar to him, the first he'd seen on his arrival, five years ago.

Five years...

In some ways, it didn't seem that long since he'd stood with his nose pressed to the transparent crystal wall of the Ark's boarding tube, watching the wedge-shaped silhouette of the Ameline fall away into darkness. For a moment, he closed his eyes and pictured Katherine as he'd last seen her: standing at the Ameline's airlock, her rumpled fatigues thrown on over her skin-tight ship suit, her hair tied back and gaze downcast, avoiding his.

When he opened his eyes, he found Harris glowering directly at him.

"I'm sorry Mister Drake, am I boring you?"

Toby jerked upright in his seat.

"S-sorry professor, I was just thinking-"

The older man raised a furry eyebrow. "Aye, and I know exactly whom you were thinking about, too. But if you don't mind...?" He turned back to the screen, which still showed the familiar depiction of the Ark fleeing the looming cloud as smaller ships wove around like mosquitoes to cover its retreat.

"The Dho call this picture 'The Burning Sky.' Whatever the cloud was, they escaped it by only the narrowest of margins, using these weapons," he indicated the stylised lightning bolts flickering from the smaller ships surrounding the diamond planetoid. "With their help, they kept the cloud at bay while making good their escape."

The professor pushed his glasses up onto the bridge of his nose. He took a deep breath, as if nerving himself.

"The fact that they used weapons against it leads me to believe that the cloud was not a natural phenomenon."

At the side of the room, the Dho turned its head a few degrees. It was a tiny movement but all eyes snapped toward it.

Harris took a step towards the creature.

"Do you have something to add?" he demanded, irritation allowing his Scottish accent to come through stronger than ever.

The creature regarded him. It seemed to consider the matter for some time. When it finally spoke, its voice was low: full of hisses, pops and scratches like a bad recording.

"The cloud is not natural," it said. There were mutters and exclamations from the crowd.

"Then what is it?"

The Dho turned to fully face the old man for the first time, although from where he sat, Toby couldn't tell if it looked at the professor or at the picture of the carving behind him.

"We call it 'The Recollection,'" the Dho said. "It is an evil born of war. It is the end of all things."

More mutters. A few shouted questions.