San Francisco is deserted, the Bay Bridge bombed, and the BART subway trains grounded. The Guardians, members of an elite and mysterious government-appointed military police force, are maintaining order at all costs--thanks to emotion-altering drugs like Emovere that suppress fear and anxiety. Lex Knightley, daughter of a prominent forensic psychiatrist, risks entering the devastated city to partner with the Resistance, a group of rebels intent upon exposing the dangers of Emovere. Lex discovers an ally in Quin McAllister, a magnetic Guardian Force recruit with a haunting past that binds them together. As she uncovers the secrets of the Guardian Force and confronts the truth about her family, Lex begins to realize that even those closest to her are not quite who they seem.