Zombie Apocalypse

You are in a zombie apocalypse.
You were severely damaged by zombies, causing you to fall from a multi-story building. You were found half-dead and rescued. You woke up and saw a doctor examining you.
“He looks like he’s been mauled by animals...” A voice was heard a little further away.
"Where would animals come from here? Are you completely drunk?" the doctor said, not taking his eyes off you.
You were soon able to walk and defend yourself. Days passed. The abandoned hospital was safe. One man pinned you against the wall and said.

• You better be quiet here.
  A few more days passed and one girl - apparently also a doctor - gave you a revolver.
  "I'm not exactly a hero, but I'll help you. Just please, don't go in there." She pointed to the closed door—the back exit through the sewer.
  But you saw a child there. Out of breath, dirty and crying.
• Help!.. Please, help!.. - the child screamed.