Calvin Penney welcomes his family home for a long-awaited reunion as an unexpected arrival makes waves throughout the coastal town of Snooks Arm.

Calvin teams up with marine researcher Dr. Fonda Howander to investigate strange events, while his son Wade tries to make sense of unsettling dreams.

Wade and Calvin encounter mysterious newcomers. Fonda warns the town's residents about a nautical threat as unease spreads through the community.

As outsiders draw Calvin into a dangerous hunt for the creature, an unseen danger begins closing in on his family and everyone else in town.

Calvin uncovers shocking truths about his past. Fonda makes a startling discovery as unexpected company arrives.

As the true motives behind the crisis become clear and an evacuation begins, Calvin, his family and Fonda devise a risky plan to save their town.