"BioShock" is set during 1960, in Rapture, a fictional underwater city. The player learns about Rapture by listening to voice recordings. Rapture was created by a man called Andrew Ryan, who did not like the political, economic, and religious powers that existed over land. He wanted Rapture to be a place where people could do and become whatever they wanted. The city was secretly built in 1946 on a mid-Atlantic seabed, using submarine volcanoes to give geothermal power. Scientific progress grew in Rapture because there were no governments or religious organizations that could put limits on research. This was how Ryan brought many brilliant scientists into the city. This led to fast developments in engineering and biotechnology. These scientists also discovered ADAM, stem cells harvested from an unknown species of sea slug, which were discovered by Dr. Bridgette Tenenbaum to have the ability to heal damaged tissue and rewrite the human genome. Tenenbaum joined with businessman and mobster Frank Fontaine to create the plasmid industry, which offered superhuman physical enhancements to its customers. Tenenbaum found that ADAM could be mass-produced by implanting the slugs in the stomachs of young girls ("Little Sisters"), taken from orphanages founded by Fontaine.