Jack is the protagonist of BioShock, whom the player controls throughout the game. He is a young Caucasian male who, prior to his unwilling arrival in Rapture, was a passenger on an airplane that crashed near a lighthouse that provided entry to the underwater city. During his journey through Rapture, he comes across a number of various gene altering substances, known as Plasmids, that he uses to empower and protect himself.
Jack is the illegitimate son of Andrew Ryan and Jasmine Jolene, Ryan's mistress. An Audio Diary by Jolene, and photos found on Ryan's desk indicate that Jack was purchased by Brigid Tenenbaum on behalf of Frank Fontaine as an embryo. Jack was to be Fontaine's back up plan if he was ever forced into a bad position by Ryan during the increasing hostility leading up to Rapture's Civil War.Jack was "born" and raised by the scientists of Fontaine Futuristics, including Dr. Yi Suchong and Brigid Tenenbaum. According to Audio Diaries by Dr. Yi Suchong, who was responsible for Jack's development, Jack weighed fifty-six pounds and had the "gross musculature of a fit nineteen-year-old by the age of one", thanks to Lot 111. Dr. Suchong also reveals in another Audio Diary that he was responsible for the mind control imprinting that Frank Fontaine requested.Jack's similar genetic structure to Andrew Ryan meant that he would be able to use the bathyspheres that were in lockdown,be resurrected at Vita-Chambers, and the automated security of Rapture would not be as effective against him.Sometime in 1958, before Fontaine faked his own death in a shoot out with Sullivan's forces, Jack was smuggled out of Rapture in a bathysphere and sent to the surface as a sleeper agent, living out his pre-programmed life until Frank Fontaine "activated" him. Upon Fontaine's command, using the trigger phrase "Would you kindly", Jack boarded a plane in 1960 that passed over Rapture's location in the North Atlantic, then hijacked it, forcing it to crash land at the coordinates of the Lighthouse, the Main entrance to Rapture.