The 1918 influenza pandemic strikes Calgary, Alberta, Canada. The Great War rages overseas. While her husband fights in Europe, Katharine works in a doctor’s office to support her children and her brother, a wounded veteran. One night their neighbour suddenly takes sick and dies. The attending doctor concludes the man died from influenza, but Katharine suspects someone laced his whisky with a drug that mimics the deadly flu’s symptoms.
Katharine convinces the police to investigate. Worried about her brother’s involvement with a suspect, she delves into his secrets and comes to fear he’s connected to the murder. She grows disturbingly attracted to the investigating detective who returns her affections. He’s convinced her brother or someone else close to her is a killer and risks his career to pursue the crime. Katharine must discover the truth so she can move forward in a world that has changed forever.