Adam's ship. A few months later.

'Adam, Eve! I'm receiving a weird signal.' said the alarmed ship pilot. 'I detected it on the radio wavelength of classical pulsar, but this one is not natural. Instead of emitting regularly, it emits on increasing frequency.'

'Wait, wait, wait, Patricia,' said Eve on the intercom. 'Why are you sure it is not natural? And anyway why should it be a problem?'

'As you asked first, the increase in frequency is neither regular nor a law of power - which might mean a pulsar is about to collide with something. In fact, the signal increases its frequency based on the Fibonacci sequence,' he emphasized, hoping in vain to be understood.

'Uh... You lost me here,' indicated Adam.

'Well, each number is the sum of the two previous numbers. It goes 1, 1, 2, 3, 5=3+2,8=5+3, and so on with 13, 21, 34, etc... There is no known cosmic event that could produce exactly this series. So it must be an intelligent species that emitted that signal...'

'And so what?' asked Eve again.

'Well, the signal does not come from the rear where we could have expected a contact from Mars; it comes precisely from the system we were targeting.'

And he might have put too much humanity in its last sentence: 'We are facing aliens!...'

'Wow,' mouthed Eve, staying immobile with wide-open eyes.

'Bollocks,' reacted Adam at the same time, but frowning like he never did before.

'Indeed,' agreed Patricia, 'it's a bit of both.'

For a moment, no one spoke. They were all dreaming, worrying and trying to think at the same time. The robot pilot opted for letting the humans do what they were best at: thinking out of the box.

'Adam,' requested Eve, 'we should answer back. I know you'll say we should concentrate on the guys who blew off the beacons, but I disagree.'

'No, No, You are right,' reasoned Adam. 'Between a friendly threat on our back and an alien contact in front, it might be difficult to choose. But we are well past the point of no return, so we have no choice: we must communicate with the aliens already inhabiting what we thought was our Garden of Eden.'

'Don't you want to contact the ship behind us or maybe Mars to warn them about the aliens?'

'Could we do that unnoticed from the aliens?' asked Adam.

'Yes, of course. And actually, since we are in the middle, any of our signals in one direction should be undetected by the other party.'

'But any message for us can be heard,' witted Eve.

'Not so much to fear on that side,' commented Adam, 'the last message before the aliens was over 6000 years ago.'

'So,' refocused the ship, 'what do you want to say to the humans behind us?'

'Quite simple,' retorted Adam. 'I want to know why they're destroying the beacons and basically what their intent is.'

'Could we asked them how is life on Mars nowadays,' implored Eve.

'Good idea, it's not too late to hear some news from a long forgotten parent,' he confirmed. 'So Patricia, prepare the message for Earth. I'll review it before you send it the good old ways. But in the meantime, we have to find a way to answer the aliens.'

'Both are already at your disposal.' replied a satisfied robot. 'As for the aliens, rather than repeating the Fibonacci series, I thought the series of prime number would be suitable to identify us as intelligent species as well.'

'Tell me Patricia, you like to be in charge, don't you?'

'No it's not that,' said the ship caught on fact. 'It's just that you don't have the mathematical training and...'

'Forget that peter,' interrupted Eve, 'he's just jealous and that's it.'

The ship stayed silent while Adam finally said: 'Can you give me a crash course in mathematics, say for my birthday?'

But it was Eve who answered and thus closed the discussion for good: 'Tell me, Adam, you like to have the last word don't you?'

***

Centaurian fleet. A few months later.

On the admiral ship leading the Centaurian fleet, the subtle pressure of long-winded games of power effectively split the crew into tectonic plates. Most were resigned to witness the occasional bursts among mostly languid periods.

Though, on the rest of the fleet the morale of the troops was not affected by the internal conflicts that were occurring regularly at the top of the pyramid. The soldiers were well-trained at not spreading the bad news, but this one was good news, and it went around fast.

'Captain, we just received a reply from the aliens.' said urgently the second in command, who had intercepted the news from the communication officer.

"Tell me!" replied the excited captain.

'That's the prime number series.' he said proudly. 'And that's the definitive proof they are an intelligent species. '

'Yes!!! I knew it!,' said the captain happily jumping around only in thought because he couldn't degrade himself down to that in front of his crew. 'They are willing to communicate so they are... friendly!' slowly spelled for the special attention of the communication officer.

'It was worth waiting two years for this message', smiled the captain. 'We've got to figure out what we could send as the next message to accelerate our understanding of their language. And that's your special task, Grischka.'

And he put a bit more pressure by adding: 'Only you can save our kind.'

***

Bird catcher number 2. Adam's time.

The blasting of Noah's ark left some traces visible even to the observers at the inner centre of the solar system. The bird catcher number 2 which was following Adam was well placed to watch the details of the aftermath. Its low resolution detector on its side has grasped the fact that there were two sets of explosion. But oddly it has never received any message.

Odd, it thought. If successful, the bird catcher number 3 should have confirmed its kill before blowing itself up. That's basic protocol. It was as if the catcher had communication issues. Or, it simply failed and the ark faked its own death. But the amount of debris, all nicely going back towards the Sun was a sure sign of a completed mission. No, they were both annihilated. Possibly by one another, and the obvious alternative came quickly, possibly by the aliens.

I should probably warn the coordinator. It made a relatively long pause for a machine. Hum, maybe no. The coordinator would surely have watched the situation unfolding and if needed it would have requested me to turn my best sensors to the area. Yeah. Waste of time... The bird catcher 2 cancelled the repositioning of his scanners.

My predefined mission was to intercept another of those ancient and foolish attempted settlement. The Real Frontier, what a foolish and arrogant name. I have to catch them pretty soon before those morons send another message directly to aliens.