Mercedes Liviane is the wife of Charles Liviane and the mother of Billy Liviane. She along with her husband were locked up and observed for years until they were freed by a guilt ridden Gina. Thanks to compensation they bought the huge Experiment Home.
As a young adult, Mercedes was a happy cheerleader who was studying hairdressing. Here she met Jacob Experiment a nerdy man who was studying science. They became friends although he always resented her. After they graduated he went on to study science further and she opened a small hair salon.
For a few years, Mercedes's hair salon was a great success but slowly, less people came and she was forced to close down. Without the shop's income, she had nowhere to go so went a to a now married and successful Jacob and asked to stay there. He agreed and took he to the blue room. She loved this room and joked that she could 'get use to it'. Jacob and Gina smiled and replied 'Don't'. That night they carried her to the observation suite. When she woke up, she was confused. She stayed in there but didn't know she was still in the house. She was very lonely until one day, Charles, another test subject came. Now she wasn't as alone anymore. Slowly she and Charles became friends and later girlfriend and boyfriend. One day, a new room was added and a new object appeared everyday. In their lonely world, this became a bit of fun for them. Sometime between the Sims 1 and 2, luck turned around for them and a guilt ridden Gina let them out. They ran for it and told the police. Gina and Jacob were arrested but released on bail by their twins. Thanks to high compensation, they bought the Experiment Home as the Experiment Family were forced to move out. They felt a bit bad about the Experiment Family having to leave and Gina's death but they were still angry. Later they had Billy Liviane and had a great life with him.