Big Sisters are tertiary antagonists in Bioshock 2 and it's online prologue, There's Something In The Sea. Like their predecessors among the Big Daddies, the Big Sisters were created to safeguard the Little Sisters from harm; however, the Sisters are much more active and far more aggressive than their lumbering counterparts - and much more dangerous. For this reason, they are employed as elite security for the Rapture Family and specifically deployed against Subject Delta as he progresses through the game.
History
Growing Up
Following the deaths of Andrew Ryan and Frank Fontaine, Rapture was left under the control of Sofia Lamb and the Rapture Family. Once she'd finished consolidating her influence over the dilapidated city, she also secured the few Little Sisters that Jack had not rescued or killed: requiring vast amounts of ADAM for her attempts at creating a Utopian messiah, she allowed them to continue harvesting it from corpses, ensuring their safety by having rogue splicers imprisoned.
However, as the years went by, this approach began to break down: as they entered puberty, the Little Sisters lost their ability to store ADAM in their bodies, leaving them effectively useless for Lamb's designs. Doubly unfortunately, their conditioning also began to break down, allowing them to see Rapture for what it truly was for the first time in years, driving almost all of them insane with fear and anger. Worst of all, thanks to the ADAM they had stored in their bodies, they had also acquired a wide array of Plasmid superpowers, along with an affinity for ADAM after years of childhood exposure, allowing them greater control over their powers than any of the splicers in Rapture.
Unable to use them for harvesting but unwilling to do away with such a valuable resource, Sofia Lamb ordered Gilbert Alexander to re-condition the ex-Little Sisters into the next generation of protectors - eventually dubbed "Big Sisters" by their younger counterparts. Once they were pacified and re-programmed, the Big Sisters were outfitted with custom-made diving suits, and put to work as security throughout Rapture: they proved efficient at sniffing out stolen ADAM and bringing the offenders to justice.
However, the Little Sister population was still in free-fall, with the gatherers either being murdered by rogue splicers or simply aging into Big Sisters; with birth rates still too low to produce viable replacements, another solution was called for. On Lamb's orders, the Big Sisters were sent to the surface in bathyspheres and directed towards the nearest coastlines...
There's Something In The Sea
Over the course of the next few months, the Big Sisters successfully abducted dozens of children from around the world and brought them back to Rapture for conversion into the next generation of Little Sisters. These children were primarily found in the coastal regions bordering the Atlantic Ocean, guaranteeing the Big Sister an easy escape once their targets had been secured; though many appearances of mysterious kidnappers were reported by horrified parents, the authorities were powerless to stop them and unable - or unwilling - to connect the cases from around the world. However, the red lights from the Big Sisters' lamps did get the attention of several UFO watchers around the world, resulting in a brief trend of "inexplicable red lights under the ocean." They also got the attention of conspiracy theorist Mark Meltzer, who spent much of this time studying the kidnappings around the world, charting the course of each abduction from one side of the Atlantic to the other.
As There's Something In The Sea continues, Mark attempts a more active role in documenting the activities of the mystery kidnappers, at one point managing to take a photograph of one of the Big Sisters (who he names "The Traveler"). Unfortunately, this results in the Traveler kidnapping his daughter, Cindy; Mark's attempts to rescue Cindy eventually bring him even deeper into the conspiracies surrounding Rapture, and back into contact with the Big Sisters once again. At one point, Mark is able to ambush one of the Protectors and throw a net over it, only for the Big Sister to easily slice its way to freedom and escape the area - shattering most of Mark's ribs and breaking his leg in the process.
After many twists and turns, Mark is ultimately able to follow the trail of clues all the way to Rapture - enough to leave numerous audio diaries through the sunken city as he attempts to find Cindy. Unfortunately, the Big Sisters are able to capture him and take him to Sofia Lamb; in a poetic touch, Sofia has him converted into a Big Daddy.
Pre-Bioshock 2
Meanwhile, Eleanor Lamb looked upon the growing population of Little Sisters with dread, realizing that her mother was almost ready to begin the creation of the Utopian - and because of the affinity for ADAM she'd developed during her days as a Little Sister, the candidate selected for transformation into this Utopian Messiah would be Eleanor herself.
Having developed a bond with the newest generation of Little Sisters, Eleanor instructed them to take a genetic sample from her long-dead Big Daddy, Subject Delta, and resurrect him at one of Rapture's Vita Chambers in the hopes that he will be able to rescue her - thereby paving the way for the start of the game.
Bioshock 2
Subject Delta encounters the Big Sisters relatively early in the game, with one of them snatching away a Little Sister moments after one of them provides Delta with his first plasmid. This one in particular remains a consistent nuisance throughout the journey through the Apollo Resort, either abducting Little Sisters before Delta can interact with them, or simply attacking him on sight; in these early combat sequences, the Big Sister cannot be killed, forcing players to outlast her until she loses interest and departs.
The first proper battle with one of the Big Sisters occurs in Ryan Amusements, shortly after Subject Delta has either freed or harvested all the Little Sisters in the area - prompting the Defender to attack in an attempt to retrieve the stolen ADAM. Over the course of the game, this pattern continues, with a Big Sister battle commencing as soon as the Little Sisters in a particular location have been dealt with. Unlike their younger counterparts, sadly, the Big Sisters cannot be rescued from their programming, and must be killed over the course of each boss battle.
However, during the climax of the game, the Big Sisters take on a new importance to the plot: when Delta is mortally wounded via his connection to Eleanor and captured by the Rapture Family, Eleanor Lamb herself takes charge of the situation by making herself a Big Sister; already possessing all the necessary powers and traits, she only requires the diving suit, which Delta can collect for her via one of the Little Sisters. Eleanor's first act as a Big Sister depends entirely on how Delta has treated the Little Sisters up until now: if Delta has been murdering and harvesting them for ADAM, Eleanor will follow suit by ripping open a Little Sister and taking the ADAM-rich sea slug bonded with her; if Delta has been freeing them, Eleanor will release a Little Sister from captivity.
The climax of the game results in a massive drop in the Big Sister population, and the events of the follow-up DLC ultimately spell the end for the last line of defenders: by the conclusion of Minerva's Den, all of Rapture's Big Sisters are apparently dead - exception being Eleanor herself.
Description
As a result of the ADAM they were exposed to over the course of their childhood, the Big Sisters experienced a an unusually pronounced growth spurt during adolescence, leaving them extremely tall even without their distinctive gear. According to documents found in There's Something In The Sea, Big Sisters have an average height of around 6' 10'', and the final chapters of Bioshock 2 show that Eleanor is able to stand eye to eye with Subject Delta. The Big Sisters also posses an extremely slender build, supported by long and remarkably skinny limbs. Though Eleanor is the only Big Sister ever seen out of her diving suit, the fact that the former Little Sisters are immune to the more unpleasant effects of splicing indicates that Eleanor's relatively normal appearance was not a fluke: most of them would have been perfectly normal teenagers under their armor.
The diving suits worn by the Big Sisters different significantly from those worn by the Big Daddies: as well as being much more streamlined, the Big Sisters were not grafted into their suits and could actually remove them - as Eleanor does during the ending cinematics. Close examination reveals that most parts of the suit are buckled or even physically braced together, further emphasizing the improvised nature of the apparel. The spherical helmet possesses a single porthole through which the Big Sister can see, and as with all protectors in the Bioshock series, the color of this "eye" is a good indication of intent - red for hostile, yellow for neutral, green for friendly: with most of the line out to kill Delta, it's not until Eleanor takes up a suit that the green indicator is seen.
Along with the oxygen tank necessary to support the Big Sister when venturing into the ocean, the suit is equipped with two prominent piece of equipment to aid her in her duties: the first is a large syringe mounted on a gauntlet; worn on the Big Sister's left arm, this foot-long needle is commonly used for draining ADAM from criminal splicers. However, it's also tough enough to serve as a very effective weapon in open combat with Delta. The other piece of equipment is a large metal basket strapped to the back: this is most commonly used to transport Little Sisters when moving them away from dangerous areas of Rapture - though the abductions on the surface also indicate that they would have also used these baskets to carry kidnapped children. As a result of their duties as protectors, Big Sisters can occasionally be found decorated with crayon graffiti and ribbons, courtesy of their younger counterparts.
Powers And Skills
Easily the most powerful of all Rapture's inhabitants, the Big Sisters demonstrate a large number of highly dangerous plasmid-based abilities: capable of pyrokinesis, telekinesis and even teleportation, they are a force to be reckoned with in combat. In addition to these active plasmids, the Big Sisters are also capable of incredible displays of strength, speed and agility: leaping into battle and charging their opponents with lightning-fast bursts of speed, they can easily outmaneuver most Big Daddies - including Subject Delta. Unlike many citizens of Rapture, the Big Sisters do not have to rely on medical kits or health stations: in the event that they have been wounded in combat, they can simply drain a nearby Splicer of ADAM to replenish their health.
Though they also possess the ability to withstand the depth and pressure outside Rapture in much the same way as Subject Delta and the Big Daddies, they are light and agile enough to actually swim through water, whereas other protectors can only walk across the seabed. For good measure, the Big Sisters are the only characters strong enough to tear through Rapture's reinforced glass without the aid of explosives, with one managing to flood the Adonis Resort by puncturing a a window during the initial confrontation with Subject Delta.
Trivia
- Initially, there was only going to be one Big Sister in the entire game, who would regularly do battle with Delta and eventually be revealed as Eleanor Lamb herself. However, this idea was eventually discarded on the grounds that it would diminish the excitement factor of the battle if the player knew that she would always escape death; the identity twist was also seen as predictable and fragmented. Instead, the Big Sister was transformed into an elite fighting force of Big Sisters, though Eleanor does become a Big Sister towards the end of the game.
- Graffiti throughout Rapture warns citizens that "Big Sister Is Watching!" a clear reference to the slogan "Big Brother Is Watching!" from George Orwell's Nineteen Eighty-Four.