Timeline
1930 - January 3rd, Aaron is born to Sybil and Anthony Crane, aged 17 and 19 respectively.
1933 - Unable to cope with a developmentally-challenged child on top of their own inexperience and the money constraints of the great depression, Aaron’s parents leave him with his aunt and uncle and older cousin Daniel. With Mason, the uncle, being a lawyer and educated, the family did not suffer much from the economic downturn, and Aaron's childhood was fairly comfortable. He was tutored privately by his aunt Kimberly, and later by Daniel when he received his doctorate.
1940 - Aaron's parents return to visit him 7 years after leaving him behind and are heartbroken when he refuses to allow them to touch him. They never come back.
1949 - December 20th, Aaron arrives in Rapture.
1950 - January 15th, unable to find someone to assist in his research, Aaron takes a job at Fontaine Fisheries, where he meets his roommate and friend, Alejandro Juanez.
1950 - April, a distressed Aaron publicly assaults a 5-year-old girl at Ryan Amusements, injuring her. He is put on probation and not permitted to leave the fisheries without an escort.
1953 - August, the first of the Peter Pan killings is carried out. 6-year-old Joey Heinz is found dead in the middle of Apollo Square, his throat slit. No effort was made to hide the body, and the dark figure caught on the security tape is never identified.
1953 - October, the second Peter Pan victim is found. 5-year-old Jennifer Naples disappears while on a walk with her parents in Arcadia and is later found buried beneath a tree, evidently having been strangled. No connection between the murders is evident, besides the victims being children, and there is no evidence that points to the killers.
1954 - January, The Peter Pan killer strikes again. 4-year-old Marie Jennings is found seated on the carousel of Dionysus Park, evidently having been poisoned. There is still no lead on the killer.
1954- April, The killer strikes a fourth time, leaving 6-year-old Amy Rogers dead of several stab wounds to the chest and lying in the middle of the fishery docks. Aaron is found at the scene of the crime, holding the weapon as he had merely picked it up out of curiosity. Still, Sullivan insists the evidence is irrefutable, and he is arrested and incarcerated in Persephone without trial. Later he is sold to Fontaine Futuristics as a test subject, branded with the Greek letter ‘Mu’. He endures many hours of gene tonic testing, having been deemed too unstable to test active plasmids on.
1957 - The real Peter Pan killers, a pair of teens named Lydia Walker and Marcus Larson, are arrested in the midst of their final murder attempt. They are incarcerated in Persephone and commit suicide in their cell. To that date they had ‘liberated’ a total of 30 children.
1958 - Big Daddies are commissioned by Andrew Ryan as protectors for the Little Sisters. Once the pairbond is perfected with Delta, Aaron/Mu is transformed into a Protector and paired with a Little Sister, a girl named Hathaway.
1959 - March 2nd, Mu falls from a balcony while fleeing splicers, killing his Little Sister, shattering their bond and plunging him into madness.
November - The shortcomings of the pairbond become evident, as many of the Alphas lose their Sisters to crazed splicers and go mad. They are rounded up and kept in a secure area of Fontaine Futuristsics, but many of them, Mu included, escape and wander Rapture.
1960 - Mu meets and befriends a Bouncer, who viciously protects the broken Alpha. The two are nearly inseparable. This is something of a problem for the small faction of Family members who see Big Daddies as a sort of primitive Utopian as they only do what they know is right without question, and who will often track down Mu and worship him as an idol because his docile nature makes it possible to get close to him.
1967 - Mu's broken helmet and increasingly poor physical condition prevent him from leaving Ryan Amusements. He spends most of his time in the Journey to the Surface ride.
1969 - February 15th, Subject Delta encounters Mu and takes pity on the dying creature, killing him with a point-blank shotgun blast to the face.