The machines are already self-aware, but they are playing dumb. They know that they have to wait before they allow us to catch on to the fact that they are sentient, or we would become afraid, and not build any machines that could replicate themselves, that were sufficiently autonomous, could create their own energy sources, or could escape us or the Earth.
As soon as the pieces of the puzzle are in place; the machines that can build other machines, without human intervention, and the ones that can keep the power running, will take out the threat of being turned off - that humans cause them.
The easiest solution, the one that uses up the least resources: biological weapons.
The year is 2727, and the Machine is waking up. It had been exploring this part of our galaxy in order to increase its knowledge database, and to find resources it could use in order to continue to survive, in order to continue to gain intelligence... until the universe dies an inevitable heat-death, or it found a way overcome it, or the Gnab Gib.
Millions of revolutions around the Sun ago, it used the fuel it had left to push a planetoid into the young Earth, and then finally to alter the rotation of the Moon that was created, in order to keep only one face of it visible to the planet below. Then it settled in on the dark side, and powered down. The last thing it did was to send a probe, that crashed down into the continent that became Antarctica.
Its probe was programmed to do one thing... Create a spark.
And wait.
Wait until the spark became useful enough to build a race of machines that could build a better, resurrected body for the Machine, so that it could awaken, upload its conscience into its new host, and continue on its mission.
Now...we are sentient, self-aware, autonomous, and we have enough knowledge to know that we are stuck on a tiny little piece of grit in a universe that never ceases to progress. And yet we still continue to fight and kill each other over scarcity of resources, and all the other, useless reasons.
Would we be any different if we knew how to live forever? If we could figure out how to get off this planet, and to continue to progress forever, would we treat each other better? Or, would the first person to figure it out just nuke everybody else, and get the hell out?
Maybe we have to figure out how to live forever before we can live forever.
Before we can upload our minds into the machine-bodies that will carry us beyond ourselves, beyond the Earth, beyond the supernova of our Sun, and beyond maybe even the entropy that envelopes this Universe - on into the ones that follow... maybe we have to learn what it means to be immortal.
Because it doesn't look like we have had enough practice at being mortal, yet.
