These Lifeless Things — Premee Mohamed

Eva is a survivor. She's not sure what she survived, exactly, only that They invaded without warning, killed nearly all of humanity, and relentlessly attack everyone who's left. All she can do to stay sane, in the blockaded city that's no longer home, is keep a journal about her struggle. Fifty years later, Eva's words are found by Emerson, a young anthropologist sent to the ruins to study what happened. The discovery could shed light on the Invasion, turning the unyielding mystery of the short war into a story of hope and defiance.