Set during the American Civil War, In a Dark Garden follows Julian Chisholm, a Confederate Army doctor who is sympathetic to the Union’s cause - despite being born and raised on a southern plantation. While he travels through several war-torn places—including St. Augustine—Julian falls in love with Jane, a Union spy who assists POWs and slaves escape to the North.

Local locations visited or mentioned include, but are not limited to Fort Marion (Castillo de San Marcos) and St. George Street.