In a small coastal English village during the 18th century, mysterious marsh phantoms bedevil the local populace. These ghostly figures are believed to haunt the night, but beneath the surface lies a deeper intrigue. Captain Collier, a steadfast Royal Navy officer, arrives with his men to investigate reports of smuggling in the area. Tasked with uncovering illicit trade hidden behind the village's facade, Collier grows suspicious of the local parson, Dr. Blyss, a respected yet enigmatic figure who wields significant influence over the villagers. As Collier's men conduct their investigation, they are met with resistance, and strange occurrences begin to suggest that there is more at play than mere smuggling operations.

With each passing day, the tension between Collier and the villagers escalates. As night falls, the ground-shaking roars of the assumed phantoms fuel fear and superstition among the locals. Captain Collier becomes increasingly convinced that the apparitions are tied to the smuggling activities. His search for truth leads him deeper into a web of deception. The village harbors secrets within its labyrinthine marshes where alliances are tested, loyalties shift, and true identities are cloaked in ambiguity. The clash between law and legend reaches a boiling point as the villagers' fate intertwines with supernatural tales, forever changing those involved. Hidden motives and unsettling truths emerge, leaving a lasting impact on both Collier and the embattled village.