When she was 5, Monica was adopted by a loving family. The father had a very little chance of having biological children of his own, as his sperm count was too low after a tragic accident. This family loved her even more than they would have loved a biological daughter because they didn't have to go through the first 5 years of misery that comes with raising a newborn child. The father was a professor of electrical engineering and the mother was the heir to a business empire. Her dad owned the leading corporation involving manufacturing and trading military vehicles.
When Monica was 15, her father found out that her mother had been cheating on him with a family member for many years. This led to their divorce. The divorce went quietly to avoid public scandals, and the court ruled that Monica would live with her father.
Years later, the outbreak happened. Monica and her dad received invitations to the crisis shelter from the mother. With the news they had been hearing about the outbreak, they decided to accept the invitation and move into the shelter.
In the crisis shelter, they stayed in a house in the section designated for the mother's family, in the middle of the walled area. The house was right next to the one where Monica's mother, her brother, and his wife and children stayed. However, it was much smaller.
During their time living close to each other, Monica's relationship with her mother improved somewhat. While it wasn't as if the divorce had never happened, it was significantly better than it had been a few weeks earlier.
After a few weeks, a surprise attack occurred. One of the military units' commanding officers, Egon, led a group of residents to an emergency shelter inside the walls, set up by the military unit for emergencies, hence the name. Monica and her father were part of that group. Her mother, however, decided to stay with her brother's family in their villa. The villa had a massive basement that served as a safe room. They believed this safe room would protect them from the impending attack. And maybe it did—I'm still deciding on that.
The attack happened. Egon, along with a few survivors, headed to the control room to check the building's systems, reset the security codes, and verify the building's functionality. By the time they gained control of the building's security and surveillance systems, a massacre had already begun. All they could see were people outside the gate, begging for it to open while they were being torn apart one by one. One of the people in the control room was Monica's father, Professor Kastner.
The first few weeks were dangerous. Factions began to form, and conflicts began to emerge. Monica and her father initially stayed with her mother's family. However, when her mother's family, along with the Baumann family, decided to isolate their section from the rest of the shelter, Professor Kastner opposed this idea and moved out before the separation occurred.
To resolve the emerging conflicts, a group of scientists and wise individuals formed the Council of Scientists, taking on the responsibility of uniting the community. The founding members of this council were Professor Kastner and Erdmann Warner. After addressing most of the major conflicts between factions, the self-formed Council of Scientists organized a general election to establish decision-makers who would act as a temporary government until the situation was resolved. This election was needed by the rapid growth in size that the Council of Scientists experienced.
Once the new system was established, Professor Kastner joined the communication team, which was responsible for communicating with the outside world and searching for possible signals from survivors of day 0. Monica decided to join her dad in the communication team and has worked there up until the story began.