The City Series3 books in series
Mordacious Publisher's Summary
From the universe of the Until the End of the World series. (Note: The City Series can be heard before or after the Until the End of the World series)
Sylvie Rossi has the loner thing down pat, with the exception of her best friend, Grace. But when the two are trapped in a hospital during the last gasp of a dying city, alone time is no longer an option. A nurse's offer of sanctuary promises Sylvie the supplies she needs to survive the zombies - it's the coexisting with people that might do her in.
Eric Forrest will do whatever it takes to get into the dead city for his sister, including ending up dead himself. He's used to taking risks, but with every mile he travels death looks likelier and likelier, and finding his sister may be his only prospect for survival - if he can make it home.
Sylvie doesn't need more than food, water, and shelter. Eric wants only to find his sister. But sometimes what we think we need isn't what we need at all, and what we find is more than we expected.