'The main way is full of legionaries!' shouted Cawl over the rush of the wind.

Another hit crimped the corridor's sides. Air whooshed loudly through holes in the metal. Cawl braked with a second to spare, coming to a halt, tyres smoking, a mere metre before the damaged section. The floor was concertinaed, and impassable.

'The cart won't make it over that. We'll have to walk. There's the door at the end. We're nearly there.'

'We're going to die!'

'Move!' Cawl shouted. The door out of the corridor lay a few hundred metres ahead. Cawl dragged Friedisch up from the cart seat. 'Move!'

Head bowed, shoulders set, Cawl half dragged the other tech-priest behind him towards the door. Tez-Lar clambered from the cart and thumped after them. The spar shook again, whipping about like a wounded snake. Cawl tumbled down the way like a stone rattled in a rations tin. He came to rest, his head spinning, and could not rise Maybe Friedisch was right. Maybe they were going to die Chemical smoke burned his nostrils. His eyes watered. The battle was coming closer. The explosions were louder. Alarms screamed from every quadrant. An iron grip snapped closed around his robes. Tez-Lar hauled him to his feet. Friedisch dangled from the servitor' s other manipulator. Tez-Lar plodded forwards as if the floor were completely still.

They passed through the door. Tez-Lar cast them into a corridor full of blessedly clear air.

Its machine-spirit honking out a doleful warning, the door closed, and a blast door slammed over the top, sealing the spar way for good. Cawl scrambled up to an armourglass window.

The void sparkled like bright sunlight on water. Ships passed each other at insanely close quarters, rolling over as they brought their full complement of weapons to bear. Void shields blazed with impact displacement. Vessels drifted, ablaze from stem to stem.

At the centre of this storm of war the Hrafnkel grappled with the Vengeful Spirit. Cawl recognised them both, such was their fame. They were brothers, equally immense, Gloriana-class battleships of the largest sub-patterns. Their kilometres-long bulks made the Heptaligon and its host moonlet seem pathetic in size. They were old warriors now, diminished in potency by war, but still deadly, and still determined to kill. Broadsides belched from the massive guns ranged along each ship's flanks, hammering into their opposite number, trading punches like ageing pugilists unwilling to give in. Their shields crackled with lightning. They were committed to a brutal slogging match that would end only when the strongest combatant remained alone, bloody but standing.