A siren began to sound, filling the vast caverns of air between the city towers.

The grubs mewled and spat at her from the door-lip where she'd been crouching only moments before. From the tentative way they poked their heads out beyond the shadows of her cell, before quickly drawing back again, she guessed they didn't have much of a taste for sunlight.

She remembered what Moss had told her before vanishing: how he intended to 'lead them on a wild-goose chase'. He had wanted her out of the way while he pursued the derelict for himself – and yet there were clues in what he'd said that made it clear he was, for reasons she didn't yet understand, working for the Immortal Light Hive.

And as for her implants – well, she'd realized something was different. Ever since the terrible migraines had begun to fade away, she'd felt an enormous sense of presence, as if something greater and more mysterious lay behind the derelict's machine-consciousness.

The more she learned, the more questions she discovered that still remained unanswered.

She stared down at the blimp as it slid up next to the wall of the tower below her, the distant siren now joined by others, echoing throughout the river valley, a discordant yet strangely plaintive sound.

Just a few moments more, just a few moments more…

No matter what changes might have taken place within her skull, her implants were receiving the same information: they leached data from Bandati weather observation stations and other sources, and used it to make precise calculations based on the current wind speed, local gravity, and the amount of push she would need when she finally jumped off the ledge and onto the blimp.

All of this was channelled to her in the form of an instinctive foreboding, an acute sense of exactly when she had to jump, and how hard she would have to launch off her perch. And when she did so, the derelict would effectively be controlling her leap for freedom.

What the hell were those sirens for? Surely she didn't represent that much of a threat that they had to She glanced up to see a brilliant, almost blinding, flash of light high up in the sky. Something was breaking through the clouds overhead, and dropping towards the city…

She screamed as, reacting in shock, she suddenly slid before managing to grab on hard to the lip. There were platforms below, but a long way down, and at the very least she'd break her neck if she fell onto one of them.

There were further bursts of light, but closer to the ground this time. Dakota swivelled her head and saw that these flashes were coming from the riverside. A closer look showed her that the points of light each rose upwards on a vertical column of smoke. They were missiles.

They shot up past the topmost level of the towers, heading for whatever it was that was now dropping down through the clouds: something heavy and black and huge.

She glanced down again. The blimp was still blithely moving towards her.

The wind keened high as it swept over her bare skin, filling her with a deep chill that had nothing to do with the ambient temperature. She focused on the wall of the tower just millimetres away from her nose.

Another flash of light, even more blinding, from high overhead.

She felt a weird ecstasy take her over, almost indistinguishable from bottomless fear. Without thinking about it, without allowing herself to ponder the decision for even one more second, she launched herself out into the air, as forcefully as she could, and fell headlong.

She dropped straight towards the blimp, but with only eight, maybe ten metres to go, she wouldn't hit too hard, with any luck.

She heard explosions far overhead, like balloons popping. More missiles?

As she dropped, a dark film slid over her vision, softening the brightness above. The something pushing through the cloud overhead had become a burning star dropping straight towards the river below her. The air was suddenly filled with a roar like nothing she had ever heard, drowning out even the ongoing cacophony of sirens.

She hit the blimp dangerously near its nose and she started to slide, grasping wildly at the netting that held the craft together. Her body was now coated in a black skin, entirely non-reflective, shielding her from both radiant and kinetic energy.

The breath had frozen in her throat, her lungs had stopped working, and even her heart had ceased its beating. The brightness above faded, the gamma adjusting automatically.

Somehow, some way, her filmsuit had activated.

The invader – there was no other way to think of it – continued to drop rapidly towards the city. Her filmsuit had adjusted to the light sufficiently, so she could make out the form of the arrival; a vessel of dark metal, its upper half roughly conical in shape, while its lower half took the form of an inverted bowl. It rode downwards on a tail of fire that pulsed several times a second. It was also, she realized, enormous.

The heat and light coming off it was so insane that if it hadn't been for her filmsuit, Dakota would very likely be dead already. Platforms up and down the tower immediately next to the blimp burst into flames – as did the blimp on which she crouched.

And yet, the invading ship had to be still at least a couple of kilometres distant. Her implants told her it was giving off enormous levels of hard radiation, while engaged in some very hard braking.

Trickles of data about airspeed, along with a chaotic running analysis of the invader, were being supplied by the derelict, but none of that changed the fact that her carefully planned escape route had just turned into a flying bonfire. The other blimps in the train had also caught fire, and had started to drift away from their programmed positions.

The blimp directly under Dakota began to tilt nose-upwards as flames consumed it. All she could do was stare at the invading spaceship as it dropped down between the towers on a tail of brilliant, flaring fire. Her implants told her it was just shy of eighty metres tall.

The blaze emanating from its underside pulsed like a strobe. An Orion pulse-ship, she realized with horror; like some relic out of the early days of human space exploration, the kind of thing that had been planned but rarely built. It was firing miniature nuclear explosives out of its single main nozzle, up to a dozen every second, using sheer brute explosive power to drop it smack in the middle of Darkwater, at enormous cost to the surrounding landscape.

She spied projections on the upper surface of the invader's hull that looked like mounts for heavy artillery – probably pulse weapons and the like.

Rising on white columns of smoke, more missiles rocketed upwards from near the river. She saw one or two find their target, but the majority were destroyed by the nuclear inferno jettisoning from the invader's underbelly, inflicting little or no damage on it.

One missile spiralled off course, rushed straight towards Dakota's tower and hit a cargo blimp at the rear of the train she had diverted.

The blimp she was on kept tipping more and more away from horizontal. A rigid metal framework encircled the gas bags that gave it lift, and by some miracle not all of them had yet caught fire. She grabbed a metal strut and held on.

The blimp shuddered, dropping faster as it lost buoyancy, until Dakota lost her grip. She slid a couple of metres and managed to grab another part of the framework. Flames and smoke rushed up towards her. She had minutes, more likely seconds, before the whole damn thing went tumbling down to the river far below.

The blimp started to rotate around its horizontal axis like a ship capsizing, turning so quickly that Dakota almost lost her grip again. She hooked her arms and legs around the strut and soon found herself hanging upside down over the city of Darkwater. She had a sudden rush of vertigo that made her head swim.