I put my tools away and lean against the wall of the Machine with arms stretched out like I'm hugging it. I listen to the endless hum change pitch and I smile, knowing I've done a good job. The others think I'm crazy, but I don't talk to them much anyway - they avoid me, steer clear of the grease and the calluses and the scars. So many scars - the Machine demands constant vigilance. It needs constant attention as well, with parts wearing out or getting jammed every day. I step to the edge, where the air whips past and threatens to pull me out into nothingness, and I close my eyes. I can feel every vibration, hear every gear turning for a mile in all directions. Something is off, something throwing the alignment out of whack as we paddle through the clouds, so I clip onto the harness and rappel down onto a swinging sail, riding it along the side of the Machine.
At the far end of its path I jump off and climb up the wall, watching as the sail folds inwards and shoots back to the front so it can begin its journey once more. It's a beautiful dance. There are so many sails, and arms, and devices. Scoops reach out to sample the ever-changing atmosphere of our gas giant, antennae expand and retract as they search for other colonies in the mists. Other contraptions operate inside the rust-colored spiderweb that covers the whole of the Machine, each thread a thick metal support. Some of these flies in the web are pumps for air and water, others are sewage processors and even weapons systems, though as far as I know nobody has ever attacked the Machine. Each one of these devices is a beautiful miracle of gears and belts and pistons - serving the ones that live inside.
I look in on the others sometimes, peeking through the ventilation ducts or finding a perch somewhere near the maintenance hatch where I won't be noticed. I just watch, looking as they scurry around in the perfect sterile environment. None of them have scars, none of them are covered in grease. I pity them. I was born to them, so long ago, but I knew as soon as I was old enough to walk that there was something more out there. I remember sitting in my smooth clean bedroom and pressing an ear to the floor, listening for the distant sounds of the Machine that surrounded me. It spoke to me, even then. The others have jobs assigned to them; tending the gardens, cleaning, making clothes - but the External Engineers are called by something within. When the job was assigned there were forty of us, or so I'm told. Now there are four, one for each quadrant of the Machine.
We ride the sails and swing through the scaffolding, and though I'm told we have assigned quarters somewhere in there with the others we prefer our hammocks, slung between two beams out in the cloud. Sometimes one will get too old or - much more rarely - too careless. They fall, or are pulled into the Machine. Like clockwork a child will sneak into the maintenance halls when that happens, they'll come like I did blinking into the light of the outside, and the others will train them. Maybe I'll even have a child of my own someday, though the other three engineers are all male so it's not exactly likely.
I find the offending part, a minor pivot in need of oil. Uncorking the bladder at my side I carefully give the Machine what it needs, and once the part is turning silently again I climb inwards until I can lean against the wall once more. I only have to wait a moment before I hear it; the humming grows deeper for a moment in thanks, the benevolent purr of the Machine.