A series of shootings exposes San Francisco to a methodical yet unpredictable killer, and a reluctant woman decides to put her trust in Sergeant Lindsay Boxer. The confidential informant's tip leads Lindsay to disturbing conclusions, including that something has gone horribly wrong inside the police department itself. The hunt for the killer lures Lindsay out of her jurisdiction, and gets inside Lindsay in dangerous ways. She suffers unsettling medical...

SFPD Sergeant Lindsay Boxer has sworn to defend against all enemies, foreign and domestic. As Lindsay prepares to celebrate her own daughter's birthday, she clashes with rising Chief Charlie Clapper over a family case. When a distraught mother pleads with Chronicle reporter Cindy Thomas to investigate the disappearance of her daughter, Tara, and baby granddaughter, Lorrie, Cindy immediately loops in SFPD. But Tara's schoolteacher husband, Lucas Burke,...