Over the next six years we fell into a comfortable routine of maintenance checks, course corrections, and consumption of assorted forms of entertainment. Mostly stored in the libraries of the ship's computer but we did get the occasional data packet from Pallas, or tried to write our own material. The memory of Stewart's weekly poetry readings still makes me gag. We also found other, non-written ways to entertain ourselves in each other, if you know what I mean. Tony was always so strong and controlling, Stewart, rather flexible if you know what I mean, while Rachel could do surprising things with those grass-clipping teeth of hers.
All this while, I was assigned to keep vigilant watch on any and all communications from home. However, after a couple years it got boring just sitting by the comm station and replying "confirmed" to every message so I set a program to respond automatically and alert my handheld comm whenever someone called. Messages were coming less and less frequently as time went by anyways.

Then, one day, it all changed.

We hadn't received any messages in three months. To be honest, it took them more than seven months to reach us by that point in our journey and an equal amount of time to get back home so the delay was understandable. We thought nothing of the long delay until one day when we received a report that chilled us to the very bones.
"Earth has been attacked." The simple text message started. "An object massing approximately ten million metric tonnes and traveling at 90% of the speed of light collided with the planet from somewhere far outside the solar system. Nothing on the surface survived, the crust was split and the mantle exposed." It ended with a line that tore at the very foundations of our belief system. "Scientific consensus is near unanimous. It could not have been natural and it cannot be the result of any action by human or parahuman technology. We are at war with an alien civilization."
Needless to say we were dumbfounded. Alien civilization? That was the stuff of old science-fiction. The humans had concluded long ago that they were the only intelligent life in the known universe, and even after creating us we weren't very alien. We just sat there in the media room staring at the last sentence in shock until finally one of us gathered themself up enough to speak.
"They're doomed." Tony said simply. "Nothing they can do."
Stewart disagreed to an extent. "They can hide. The aliens have only attacked Earth. It said nothing about the Asteroids or Mars domes or the Venus aerostats. If they dampen their emissions to background levels they might avoid detection and escape further attacks."
"Dampening emissions sounds like something we could do." Rachel cut in. "I could shut off the active sensors, rely on passive only. Maybe even cut the drive to minimal pulse. But that would vastly extend our travel time to Epsilon Indi."
I asked her, "How much longer?"
The bunnymouse sighed. "Eighty years, give or take." She leaned forward on the table and groaned. "We might not live that long."
Humans can live about a hundred years, given proper care is taken. On the other hand no one knew how long parahumans could live, the oldest of us would only be in their fifties by now. Still, we were already twenty. The odds of us living through another eight decades seemed slim.
Stewart, of course, had worked out another answer. "We have the life support capacity to sustain three times our number, indefinitely. We could, you know…"
I looked up. "Lay our hopes and dreams on the next generation?"
The weasel mix grinned. "You were always a better poet than I."
Tony the bear-tiger snarled to bring the meeting to order. "We still need to figure out how to avoid the same fate as Earth." He said. "Have you sent a reply?" He directed straight at me.

"No, I..." I stopped. The machine would have sent a reply automatically upon receipt of the message. Just a brief confirmation code but it would still be a traceable signal. "I need to go change some settings." I rushed off before any of them could ask me what was wrong.

That night I spent in Tony's cabin, his body substituting for a blanket. I felt so vulnerable, so scared of what might happen next, and his pseudo-ursine arms felt safe and secure. No matter how little they might actually defend against that which now threatened us.
Some time after we'd finished our love-making I found myself muttering "I doomed us." As I lay there under Tony. At the sound of my voice he snorted awake and looked at me quizzically. I adjusted my position to look him directly in the eyes and elaborated. "I set up an automated response to Earth years ago. We sent back a message that will lead the aliens straight to us."
He paused for a minute, trying to formulate his response in a way that wouldn't make me even more upset. "Lisa," he said, for that was how we liked to shorten my name. "That message was on a tight-beam, correct? Going only to Pallas?"
"Yes." I confirmed, feeling maybe the faintest hints of relief. "But what if they attack Pallas and set up a listening station there before the message reaches Sol? Then we're done for."
He chuckled as if he were one of our instructors back in training and I had just asked a silly question. "I very much doubt that." The tiger-bear said. "It will take less than a year for our message to reach home. Their use of a relativistic "sniper" shot from outside our detection range indicates that they didn't want to risk a full-out confrontation with Earth so any invasion force would be at least a light-year out. Nothing capable of thinking, or even computation, could survive the acceleration needed to get a ship that far away to Sol before the message arrived."
Tony seemed to be making sense, I wasn't an engineer like him or an astronavigator like Rachel, but I knew the detection range of a starship-sized object using Earth's telescopes. It was, in fact, over 1.1 light-years. But, something that had long been dismissed as fantastical rose to the front of my thoughts. "What if they have faster-than-light drive?"
Tony actually laughed out loud at that. "Don't be ridiculous." He exclaimed. "Not only is that impossible, but on the long chance that they did have FTL they wouldn't have bothered accelerating that giant rock up to .9c. They could have just "warped in" a bunch of nukes near all our major population centers." He waved a hand idly as he spoke. "It costs so much energy to accelerate something that large to that speed and it is detectable from so far away that they wouldn't have bothered if they could bypass the speed of light barrier."
I finally was able to relax then. If he was so sure that we were safe, then it was so. It could be no other way. I drew my arms out from under Tony and wrapped them around his thick chest. "I definitely want your children." I told him.
He laughed again. "What? Going to leave poor Rachel stuck with Stewart?"

"Oh, you know him. He'll probably insist that we 'mix-and-match' mates for maximum genetic diversity or something like that." There would be time to work out the details of who would be having whose kids later, we had nothing but time to waste now.

For four years we heard nothing else from home. We kept on going almost mechanically. Throwing ourselves into our work to distract ourselves from the literally world-shattering revelations. In every moment of idleness our minds crept back to thoughts of habitat domes exploding under a rain of alien fire. We ran through the entertainment library's collection of any and all media that didn't involve alien invasions and strained the synthesizer's ability to produce stimulants to keep us from sleeping, and dreaming, as little as possible.
When we couldn't avoid it and had to sleep we dreamed horrible dreams of the worst things our subconscious could invent. Spidery walkers multiple stories high striding through habitat domes stomping on pedestrians. Swarms of glistening grey assemblers turning people into rubbery monsters with too many tentacles and feelers (if any octopi are listening, no offense), and worst of all: unseen snipers launching planetoids at Pallas, shattering it into a million shards of rock and dust without ever revealing themselves.
Finally, we heard something back from Sol system. Unlike the tight-beams sent from Pallas, this was a broad-spectrum transmission sent in all directions at once. I still have a recording, I might as well re-transmit it now, even though you've probably heard it already.
"This is an automated beacon broadcasting what may well be the last message ever sent by the human race. Five years ago, our homeworld, Earth was struck by a moon-sized projectile travelling at 90% of the speed of light. The debris took out most of our habitats in Earth's orbit, a few million of us survived elsewhere in the solar system. Then the rest of the invasion force arrived. Machines, vast machines kilometers in length that home in on any sources of radio transmissions, and annihilate them. We pray they are not intelligent and are simply weapons fired by a xenophobic alien race. But they've almost completed their work, we estimate that there's only a couple hundred of us left in the system. We're sending this message in hopes that there is someone out there who can hear it and beware. This universe is more hostile than we thought. They attack radio transmitters, dismantle whatever devices you are listening to this on before they find you."