As Long As We Have Eachother

Fenix, a virus. A very dangerous virus in fact. Fenix had killed almost every living thing on this earth. As far as Zach knew, he was the only human left alive...
Zach was heading south. To get away from the cold? To maybe find other living people? He didn't know himself. All he knew was that he was heading south.
But what happens when he suddenly finds other humans alive? What happens when he starts getting feelings for one of them?