Grace was homeless, Mark was a thief and Luke was a doctor. Under normal circumstances, the three of them might never have met and become friends, but a two-year long outbreak causing the residents of Manchester to display zombie like characteristics, threw the three of them together. Even after the outbreak is over, they struggle to get on with their lives and find peace with what they went through and had to do to survive, but it's hard to believe it will ever really be over.
