Marcy and her sister Jamie's life prior to entering Hawkins Lab, as well as the circumstances under which they arrived, is unclear, with both of them having few memories of their past, remembering only the time when she and her sister went to a toy store and looked at a dollhouse. According to Dr. Brenner, Jamie and Marcy lived in an abusive household which later mysteriously burned down, killing their parents and the rest of their family. After this, Dr. Brenner brought Jamie and Marcy back to Hawkins Lab, where they were given the numbers "009" and "09.5" and experimented on alongside Eleven, Eight, Six, Three and presumably other children possessing supernatural abilities. They would frequently play together in the rainbow room with Eight and Eleven.
In 1978, she sat in on one of her Sister's experiment with Dr. Brenner, Six, and Three. During the experiment however, Nine lost control of her powers and burned a lab technician to death from the inside out. Nine was placed in a coma, and Marcy stood by her side.
The next day, when Francine was in the hospital, Marcy went over to Francine and lied next to her in the hospital bed. After sleeping for a few hours, she was woken up by Francine, who told her that she was going to have to say goodbye to her sister, and that in case anybody is watching, nobody could realize it. Marcy went over and said goodbye to her sister, and then suddenly an alarm started blaring throughout the lab. She followed Francine as they ran through the lab, soon meeting up with Ricky, and all three of them ran through the lab and down into the basement, soon making it to the parking lot. Before they could get to the woods however, they were stopped by Connie Frazier and a group of security guards pointing their guns at them. Marcy watched in horror as Francine jumped in front of her and Ricky, getting shot and falling to the ground. She escaped into the woods alongside Ricky, telling him how Francine promised that she would watch out for her, with tears streaming down her face.
|Volume 2 appearances|
|Stranger Things: SIX Issue 1||Stranger Things: SIX Issue 2||Stranger Things: SIX Issue 3||Stranger Things: SIX Issue 4|
|Hawkins National Laboratory|