you where specimen #3, also called big brother. your story and named was long since forgotten, and your purpose was to pacify any intruders, by ANY means, necessary! be it splicers, ravaging big daddies, or anything else that was threatening rapture and or it's inhabitants. you are also supposed to protect the little sisters, should their big daddy's, not be able to, for whatever reason.
it was quiet in rapture, as it often was. most splicers were killed by now, either by the human, who escaped, delta, a big sisters, or you. and all the ravaging big daddies, were also gone. it gave you time to think, although you didn't have much to think about, but still.. it was nice. then suddenly you hear a weird sound, and in half a second, you had turned your XL drill rivets, with termite coating, at the source, and saw a HUGE creature, swimming through rapture! it was dark blue, using it's back part to move forward, and small growths on it's side to steer, looking a little like small versions of the big one, it used to swim forward. large eyes, and a absolutely HUGE mouth, opened and the water and fish poured inside it's mouth. it swam past the corridor you were in... slowly.
it looked docile, but you knew better than to trust anything, you didn't know. so you kept your rivet gun pointed at it, ready for anything. but as fortune would have it, it simply continued to swim.. slowly.. away.. letting out another weird almost vailing sound, before fading into the darkness of the ocean. you wait for a little while, before slowly lowering your weapon, taking one last look in the direction where the creature went, before you continue your patrol. you felt a weird feeling, in your chest.. a pain.. but according to the screen inside your helmet, your vitals were normal. your heartbeat where 90 times, a minute, which was normal, when you were relaxed. you shrugged it off, as nothing, and kept walking the empty halls, of rapture.
hope this was enough to inspire someone, as i would LOVE to see some additions to the story! :) edit: 17:20 22.02.2016 no additions to the story. which is too bad, but oh well. i'm just correcting some spelling errors and adding more stuff, if i can think of it.