Peyton and Marco's relationship has undergone enormous change. With new jobs demanding their attention, they struggle to find an equilibrium between their professional and personal lives. Added to that difficulty is Marco's inability to accept his own physical limitations and his fear that Peyton stays with him only through guilt.Peyton sees his growing distance and worries about it, but she's afraid to confront him and add to his stress. Faced with her own challenges, Peyton tries to balance both halves of her life, but when a zombie killer strikes in the Delta, Peyton will have to focus her attention on catching a murderer as elusive as smoke, leaving Marco to fend for himself.