The Territory Series by Justin Woolley

Stranded in the desert, the last of mankind is kept safe by a large border fence ... Until the fence falls.Squid is a young orphan living under the oppressive rule of his uncle in the outskirts of the Territory. Lynn is a headstrong girl with an influential father who has spent her entire life within the walled city of Alice. When the border fence is breached, the Territory is invaded by the largest horde of undead ghouls seen in two hundred years... moreStranded in the desert, the last of mankind is kept safe by a large border fence ... Until the fence falls.Squid is a young orphan living under the oppressive rule of his uncle in the outskirts of the Territory. Lynn is a headstrong girl with an influential father who has spent her entire life within the walled city of Alice. When the border fence is breached, the Territory is invaded by the largest horde of undead ghouls seen in two hundred years. Squid is soon conscripted into the Diggers—the armed forces of the Territory. And after Lynn finds herself at odds with the Territory's powerful church, she too escapes to join the Diggers. Together Squid and Lynn form an unlikely friendship as they march to battle against the ghouls. Their journey will take them further than they ever imagined, leading them closer to discovering secrets about themselves, their world, and a conspiracy that may spell the end of the Territory as they know it. less

The battle was only the beginning; the real danger is beyond the fence ...The Diggers have been destroyed, a horde of ghouls is moving inland and the High Priestess has seized control of the Central Territory. Together with Nim, a Nomad boy seeking vengeance against the ghouls, Squid and Lynn begin their long journey toward the city of Big Smoke, a city that may not even exist... moreThe battle was only the beginning; the real danger is beyond the fence ...The Diggers have been destroyed, a horde of ghouls is moving inland and the High Priestess has seized control of the Central Territory. Together with Nim, a Nomad boy seeking vengeance against the ghouls, Squid and Lynn begin their long journey toward the city of Big Smoke, a city that may not even exist. Pursued by forces that wish to see them fail, facing threats on all sides and conflict from within, Squid, Lynn and Nim search for a weapon against the ghouls. It is a search that will lead them into forbidden lands where long-held beliefs about their world are tested and Squid may finally unravel the truth of his identity. But even if they survive their journey, the teenagers on whom the fate of the Territory now rests have no idea what dangers await them beyond the fence. less