Josh Hartnett Faces a Terrifying Mystery Beneath the Water in Netflix Thriller Below

Josh Hartnett is heading into dangerous waters in Netflix’s new thriller Below, and the first full trailer gives viewers their clearest look yet at the mysterious creature threatening a remote Newfoundland community.

The six episode series arrives on Netflix on 8 October 2026 and stars Hartnett alongside Mackenzie Davis and Stranger Things actor Charlie Heaton. Netflix released the full trailer on 10 September, revealing more of the family drama, local mystery and escalating threat at the centre of the story.

Hartnett plays Calvin Penney, a stubborn but big hearted fisherman living in the small Newfoundland community of Snooks Arm. Calvin is a single father of three who is still haunted by the mysterious death of his own father decades earlier.

When a violent creature begins terrorising the coastal town, Calvin is pulled into a fight to protect both his family and a community already struggling with a disappearing way of life.

Mackenzie Davis plays Fonda Howander, a marine biologist who joins Calvin in trying to uncover exactly what is happening beneath the water. Charlie Heaton plays Calvin’s son Wade Penney, who begins displaying alarming symptoms as the mystery develops.

The wider cast includes Willow Kean as Ruth Penney, Ruby Stokes as Mary Penney, Rohan Campbell as Jay Penney and Kaleb Horn as Noah. Natasha Henstridge and Mary Walsh also appear in the series.

Creator Jesse McKeown previously worked as a writer on The Umbrella Academy and 19 2. He has explained that his own connection to Newfoundland helped inspire the series, with the location becoming an important part of the story rather than simply somewhere chosen for filming.

That authenticity extends to production itself. Below was filmed in Newfoundland, with the cast and crew working on location around the province and out on the ocean. Heaton has described filming on the water without relying entirely on studio environments, while Hartnett spent time learning more about the area’s history, fishing culture and distinctive accent.

Netflix’s trailer opens with a house being transported across the sea before something suddenly pulls it underwater. From there, the footage moves between damaged boats, frightened residents, strange physical symptoms and Calvin’s growing determination to discover what is attacking the community.

McKeown has described Newfoundland as rugged, isolated and potentially frightening while also highlighting the warmth and humour of its communities. That contrast appears central to the series, with the threat from the sea colliding with a story about family, resilience and people trying to protect the place they call home.

Hartnett has enjoyed a major return to high profile film and television in recent years through projects including Oppenheimer and Trap. He also serves as an executive producer on Below.

Davis will be familiar to viewers from Station Eleven and Speak No Evil, while Heaton remains best known globally for playing Jonathan Byers in Stranger Things.

Watch the Official Trailer:

Netflix has now released the full official trailer for Below ahead of its October launch.

Netflix has confirmed that all six episodes will be released together on 8 October 2026, meaning UK viewers will be able to stream the entire story immediately rather than waiting for weekly episodes.