Netflix has released the first teaser trailer for Below, a six-part limited series starring Josh Hartnett as a fisherman haunted by his father's death — and by something lurking off the coast of Newfoundland.

The series centres on Calvin Penney, a small-town fisherman whose father died under mysterious circumstances. When an unidentified sea creature begins terrorising his hometown, Calvin is pulled into something far darker than grief. Charlie Heaton, known to audiences from Stranger Things, plays Calvin's son Wade. Mackenzie Davis plays a visiting marine researcher. Netflix's own Tudum site describes the show as a "thriller series" (Deadline).

The cast extends well beyond its leads. Ruby Stokes plays Mary Penney, Kaleb Horn plays Noah, Rohan Campbell plays Jay Penney, and Willow Kean plays Ruth Penney — a family ensemble at the heart of the story (Deadline).

Jesse McKeown created Below and serves as its showrunner — the person who runs the writers' room and oversees production. The executive producer roster includes Jessica Rhoades (via her production company Pacesetter), Chris Hatcher, Hartnett himself, Jamie Childs, Louise Sutton, and Sharon Hall (Variety).

The series was filmed on location in St. John's, Newfoundland — the same rugged Atlantic coastline where the story is set. Netflix first announced the project in February 2025, placing a straight-to-series order, meaning no pilot episode was produced before the full season got the green light (Variety).

Below will get its world premiere at the 2026 Toronto International Film Festival on 10 September 2026, as part of TIFF's Primetime programme, which showcases television series on the festival circuit (Variety). TVLine also covered the teaser release on 28 July 2026 (TVLine).

For viewers, the teaser offers the first real look at a project that has been quietly building since its announcement eighteen months ago. A limited series format means the story is designed to land across six episodes and conclude — no open-ended multi-season commitment, just a single contained arc. Whether the creature itself stays beneath the waves or surfaces in full view is a question Netflix is holding back for now.