A few seconds later, a variety of phones and other communication devices sounded alarms. The warbling, cheeping and vaguely familiar theme songs sounded incongruously loud in the sudden silence in the restaurant. The alert noises included my own device, which beeped assertively. I grabbed it from my pocket, thumbed the privacy sensor and read the urgent message that it projected directly into my eyes.

"I've got to go," I exclaimed breathlessly.

Nobody was paying any attention to me. My dinner companions were inspecting their own phones, judging by the distracted stillness that most people exhibit when interacting with such devices. As one, John and Adele looked up at me, their eyes wide in shock. Henry's attention was still diverted by whatever communications were being displayed by his phone.

"Something bad's happened," John said flatly.

I nodded my agreement. I already had a strong suspicion what had just occurred, but the key question was why it had occurred.

My message told me that there was an emergency all-hands meeting in fifteen minutes in main conference room. This was the largest meeting space on the Endurance and not very often used, virtual meetings being so much more convenient. Indeed it was usually broken up into a multiplicity of smaller spaces and even then they were not so frequently used that it was difficult to book a room. Even so, the conference room was nowhere near large enough to hold all crew members - most people would be attending virtually - but for some reason I was one of those selected to be present in person.

Captain Edith Tan stood on a raised dais flanked by almost all members of her senior team. Tan was a petite woman with clipped black hair and ever-mobile eyes that suggested they missed little and understood far too much. She was widely respected, known to be decisive when needed, but prepared to listen to arguments from all sides before coming to a decision. She cut a diminutive figure alongside her deputy, Bruce Atherton, a tall and still bronzed Australian who always managed to look as if he had just stepped off the beach.

Captain Tan cleared her throat, which also had the desirable effect of instantly creating near silence in the room.

"Firstly, in case some of you are unclear, we are no longer accelerating. The main drives are off, and the inertial fields are powered just enough to give us near-normal gravity. On behalf of all of us, I like to thank Katrina and her team for a smooth transition - although personally I had hoped we would not have to test these particular procedures quite so dramatically!"

There was a ripple of applause around the room, with a distinct murmur composed of continuing worry and heart-felt relief as people began to realise how close to sudden death we had all been. I half-stood, raised a hand in acknowledgment, and then sat down again as quickly as I dared.

As I had guessed, the ship had performed an emergency all-engines-stop. Of course, the immense energies of the fusion reactors could not just be switched off in an instant but had to be ramped down carefully over a substantial fraction of a second. This shutdown had to be carefully coordinated with a corresponding reduction in the inertial fields to prevent a sudden and life-threatening force flattening everybody aboard.

The bang we had heard earlier was these choreographed procedures happening under the control of the automatic control systems. It was one of numerous scenarios I had studied and simulated on numerous occasions, reflecting my best understanding of the process in the programming of the computers. In any case, it must have worked reasonably well since we were all still here to talk about it.

"The reason for this unprecedented reaction," Tan went on calmly, "Is this development."

She nodded to a colleague. The screen behind her began to show footage from one of hundreds of hardened cameras which littered the surface of our little world. The view was of the near-featureless icy surface, dull and grainy under whatever limited illumination and image enhancement processing could supply. A couple of elements of the carbon-fibre web could be seen, incongruously black and shiny against the faintly mottled ice.

Al first, there was no sign of movement. Without warning, a deep chasm opened up, moving like the opening maw of a disguised deep-sea creature ready to swallow some hapless minnow. From within the massive fracture, fragments of ice large and small could be seen spinning off into space, propelled by whirling storms of gas.

Comets, which are iterant ice-balls much like this one, usually start out-gassing as they approach the warmth of the sun, often throwing off an appreciable fraction of their mass as gas and icy rubble and, in extreme cases, splitting into multiple fragments. It was clear to all that there was a risk that this could happen to us.

"The crack stabilised and refroze almost as soon as the engines had cut-off," the dry voice of Captain Tan cut across the collective gasp in the room, "So we are in no immediate danger. But early indications are that we will not immediately be able to resume our previous acceleration. Indeed, we may never be able to accelerate at such a rate again."

The screen clicked off.

"We are probably out of danger from pursuit from the Consolidationalists," the Captain continued flatly, "But we do have a fairly obvious problem. If we are not able to decelerate at our planned rate, we will not be able to rendezvous with the Tau Ceti system. Or any system at all."

The room was silent as everyone digested this information. Unbidden, the thought arose in my mind: we're doomed to travel forever.

Some panicked voice from the middle of the conference room, one which will probably be forever anonymous, spoke loudly in the stunned silence.

"What are we going to do?"

Part 3 Part 5