him with a plasmid that can remove the sea slug from their bodies and free them of their brainwashing. Jack eventually works his way to the bathysphere, but Ryan destroys it before Jack can reach it. Infuriated, Atlas has Jack fight his way through various districts toward Ryan's lair, forcing Jack to contend with Rapture's deranged citizens along the way: such as the mad surgical doctor J.S. Steinman and insane artist and musician Sander Cohen. Eventually, Jack enters Ryan's office, where Ryan is casually playing golf, and explains Jack's true origins. Through his dialogue and the evidence the player can gather up to this point, it is revealed that Jack is actually Ryan's illegitimate son, sold by Ryan's mistress as an embryo to Fontaine, who then had Tenenbaum and Suchong rapidly age Jack into adulthood and turned into an obedient assassin, capable of accessing any of Rapture's systems locked to Ryan's genetic code and thus ensure Fontaine's victory in the war. Jack was then smuggled to the surface with false memories of a normal life, waiting to be called back to Rapture when needed. Ryan suddenly takes control of Jack's actions by asking, "Would you kindly?"; Jack realizes this phrase has preceded many of Atlas' commands as a hypnotic trigger, forcing him to follow any orders without question. Jack also realizes he was responsible for the plane crash, having read a letter onboard containing the same trigger phrase. Ryan chooses to die by his own will and compels Jack to beat him to death with a golf club. Atlas then reveals himself to be Fontaine, having faked his death and used "Atlas" as an alias to hide his identity while providing a heroic figure for the poor to rally behind. With Ryan finally dead, Fontaine takes control of Ryan's systems and leaves Jack to be killed by hostile security drones. Jack is saved by Dr. Tenenbaum and the Little Sisters, that had been cured, and is helped to remove Fontaine's mental conditioning, including one that would have stopped Jack's heart. Jack pursues Fontaine to his lair, where Fontaine transforms himself into a blue-skinned humanoid creature by injecting himself with a large supply of ADAM. The Little Sisters aid Jack in draining the ADAM from Fontaine's body and eventually kill him. The ending depends on how the player interacts with the Little Sisters: If the player rescues all or all but