Due to a pandemic, the island of Alistria is quarantined. There have been resource shortages and its population has grown disillusioned. A group of revolutionaries, known as the Alistrian Liberation Citizen's Army, rises from the unrest, seeking to overthrow the government; civil war proves inevitable.

Sophia Waldron had a happy life with her young daughter, wedded to a good man that accepted her regardless of her mixed blood. However, the violent revolutionaries murder her husband and kidnap her daughter. With nothing to her name and her family lost, Sophia seeks vengeance for her grief.

Groundless follows Sophia, an unexpectedly talented sniper, who fights alongside the colorful militia from the town of Dascia. As they look for ways to ensure the survival of their town, Sophia and the partisans must constantly ward off the threat posed by the brigands known as the Liberation Army.