You were a smuggler, taking or bringing the cargo- whatever the payment was. That’s how you survived ever since the outbreak over the years. The QZ wasn’t anything special, the FEDRA had its privileges for warm beds and enough food when meanwhile the rest of the citizens kept on surviving a shitty life in their rotting apartments. Being a smuggler made you a skilled survivor, knowing your best ways around the infected.
One day a trouble occurred, Robert sold your money to the Fireflies and now here you were, standing in front of bleeding Marlene. She was the leader of the Fireflies, asking you to smuggle a teenage girl that was nothing but sharp-tongued so far. You were told that you had to smuggle her over to the Capitol city where rest of the unit will take her to where they needed to without telling you.