Adam's brain was replaced by a research probe from the future. It gave Adam his own personality and made him able to move, talk and think like humans.
Joseph Montague wanted to use Difference Golems to liberate humans from slavery and dangerous work. He wanted to change society for the better. However, after the Bloody Sunday in 1887 Joseph Montague feared that the Difference Golems would be used as instruments of injustice or terrible men of war. Joseph Montague shut down his factory only Adam remained.
Someday after this Joseph's youngest son James went along Adam to a large lake. James was showing Adam a game called ducks and drakes, when Adam suddenly had a black out. Adam did not remember what had happened, but when he came to his senses James was lying in the water and wasn't moving. Adam thought that James had either slipped or something bad had happened. Adam pulled him from the water. James survived, but no one ever trusted Adam again. Joseph soon discussed the concept of sleep with Adam and put Adam to sleep by deactivating him.
When Adam was deactivated part of him was still aware of the passing months and years and part of him still existed in the darkness. Adam felt lonely.
In 2011 Adam was reactivated by Sky Smith. He didn't want to be alone. He went to Joseph Montague's old factory, where Joseph Montague had left the unfinished Difference Golems. Adam let them come to live by putting parts of his mind into the robots, whom he called his children. He soon realised that each time he gave them the spark of life he was diminished by the process. Sometimes he even seemed to forget who he was. Rani Chandra convinced Adam that he couldn't keep up dividing a brain like that. Adam took out the research probe of the brain and gave it to his daughter who promised to bring the probe back to the future. After this Adam's mechanical body was just as lifeless as his children. However he lived on and managed to get the daughter that later tried to bring him or the probe back to the future. (AUDIO: Children of Steel)