It was exciting, but it didn't seem like a problem at first. A few ships turned up, stayed in orbit for a few days, and left. People were mainly upset because they hadn't had a chance to make contact with the visitors.
Then the ships came back again, and this time they landed. No-one came out of them this time either, unless the thing we all thought looked like a Martian Rover was actually a person. Then they went away again.
The third visit set up a base. Just a little ring of sealed habitats to one side of their ship where they'd landed in the back Bourke somewhere. If they were getting water from anywhere, then it must have been by drilling down into the artesian basin below. They ignored all attempts to contact them, including knocking on what appeared to be the front door, stayed for a year, and then left.
The next time we saw them, there were thousands of ships, and they just landed everywhere. This time they weren't shy about coming out of their ships, and were suddenly everywhere. The Storg were sort of bipedal, but they had six paired limbs, one set of which could be used for either locomotion or manipulation. They had hide, physical and gall; their green, lumpy skin was tougher than human skin, and they just took anything that they wanted. They went places and yelled at people in their own language, apparently for being where they wanted to be. They acted, someone said, like entitled tourists.
Then the second wave of ships turned up, but they stayed in orbit. There were broadcasts from orbit that we could pick up but not understand, but they were recordable so that gave us something to go on. Then the second wave of landings started, but these were targeted at the ships already on the planet and carried troops. There was screaming and mayhem in the streets as Storg chased Storg, and captured Storg were dragged off in chains to the new ships. When all the old Storg had been captured by the new Storg, the new ships rose up in the air again, destroyed the old ships, and went back to orbit. Neither side payed any attention to us, to the extent that the new Storg didn’t care what they broke of ours or what they did to us while they captured the others and destroyed their ships. People were trampled, and cities burned. We lost forty of the world's hundred biggest cities.
When the last of the Storg were back in orbit, swathes of Earth were devastated, eighty percent of the planet had declared an emergency, and the only disaster free continent was Antarctica, probably.
It took us a while to get a grip on what the Storg had been saying, partly because we had other things to worry about, but when we did it seemed that we'd been collateral damage in a police operation. The aliens weren't called the Storg, Storg was a gang name. The attack and capture thing had been a wave of arrests made by law enforcement authorities. We weren't quite sure if the gang's ships had been destroyed because they were part of a criminal enterprise or to stop us getting our hands on them. It would be fair to say that humanity was, collectively, unimpressed by the methods demonstrated by the offworld authorities.
Particularly when investigation started showing that for all their destructiveness of our built environment, they weren't that effective at destroying their own ships. We scavenged bits from all over the planet. Engineering teams, tinkerers, and scientists from everywhere compared pieces, pieced things together, and formed hypotheses. Someone found a working entertainment unit with its own power supply, recorded what they got it to play, and that gave us more language information. Several other groups managed to put together a working power plant, someone else came up with a model of how the ship's drive systems had worked.
Then the ships came back. The ships from the first landing this time, we were able to compare pictures and the markings were the same. They landed at their previous base site, and this time the contact party we sent was more insistent. The being who finally opened the hatch was the same size as the Storg and their opponents, but the lumpy skin was blue and brown. During their first landing we had been 'should we disturb the great and powerful ones if they don't want to talk to us' but now our representatives were 'Oy! About this mess your family made of our property - what are you going to do about it?', and this offworlder wasn't quite sure why, at first. Some awkwardly worded exchanges later, it was established that the base-building group thought we'd had a war while they were gone, so we showed their representative some news video footage.
At that point their representative developed a panicked look, and our experiences had taught us what a panicked look was for their kind. Then it said it had to talk to its superior and dashed back in through the hatch. Our party waited five minutes, and started knocking again. Ten minutes later two blue and brown, six limbed offworlders came back through the hatch, and the knobblier one tried to say soothing things. Frankly, they didn't translate well. Our representatives told them that we wanted compensation from their government for the damage to our infrastructure and our population losses.
The knobblier offworlder asked us what the government had to do with it.
Our representatives pointed out that law enforcement is a government function among our people. So, if not the government, who had been putting the Storg in chains and taking them away?
Our contact party came away from the meeting with a lot of diagrams drawn on butcher's paper, a lot more vocabulary, more grammar than they'd had before, and some very interesting social/political data. The contact party wasn't surprised when the base builders left the planet again in the middle of that night. The camouflaged monitoring stations we'd set up their base picked up some very useful information about the way their ship's engine worked.
It helped a lot in getting our own prototype engines working, and then in improving them so they'd work without killing people.
According to the knobblier offworlder, their people are called the Irguid. What we would call their official government, the one that deals with roads, armies, and collects taxes, they call the Generalgood - it seems our closest word would be commonwealth. The blue and brown ones were explorer/scientists working for the Generalgood, and their task was to gather data meant to inform a decision as to whether we should be contacted by their people. It was not their job to talk to us, and our reaction to not being responded to was part of their data.
Their other governments include the Shadowforum, which seems to be a mixture of criminal and special operations types, The Storg gang had gotten themselves on the wrong side of the Shadowforum, and in return they'd been crushed by the Shadowforum enforcers. The enforcers were technically law enforcement officers, but, frankly, not as we knew them. The knobblier offworlder had been surprised that we might expect either the Generalgood or the Shadowforum to make good the damage caused by the enforcers; the Generalgood because the enforcers weren't their responsibility, and the Shadowforum because they don't compensate people for being jumped all over in the normal course of business.
Naturally, our planet having been incidentally devastated by the enforcers' law enforcement action was so outside the explorer/scientists' protocols they needed to seek guidance from their home organisation. In person, apparently.
That's fine. By the time they come back, we should have stretched our expanse beyond the Moon's orbit. When we get where we're going, I don't think the Shadowforum will be happy to see us.