HBO’s new limited-series The Third Day wants to be a puzzle, but any audiences familiar with The Wicker Man, Midsommar or even Netflix’s Apostle can see what lies ahead for the visitors to the mysterious island of Osea.

High on atmosphere, The Third Day doesn’t seem to offer viewers much in its slow reveal. With episodes one and four screening as part of TIFF’s Primetime programme, it offers an introduction to two parts of the same story: the first centered on Sam, played by Jude Law, and the second on Naomie Harris’ Helen.

Both are visitors to Osea, a small British island community that is only accessible once a day by a causeway that disappears when the tide comes in. With the conveniently spotty telephone service, it’s a remote place filled with some really weird villagers preparing for a mysterious Celtic festival in Sam’s story. Yeah, you know what’s about to happen here.

Sam’s story is presented in the first three episodes of the miniseries called “Summer”, while Harris’ story unfolds in the later three episodes dubbed “Winter”. Visiting the island in each season gives a chance to relish the show’s stunning visuals, including the bird’s eye view of the vanishing causeway. Though it may be predictable, at least it’s visually appealing.

In both episodes, the unease grows when, naturally, they each find themselves unable to leave Osea. Luckily for Sam and Helen, the kind pub and inn owning couple (played by Paddy Considine and Emily Watson) are here to help, until, one can assume, they are not. We’ll venture a guess that it all comes to a head by the visitors’ third day on the island.

This horror fan would like nothing more than to be proven wrong about where Sam and Helen’s story takes them, but nothing in either episode indicates a surprise is in store for anyone other than the lead characters.

The six-part series debuts on HBO on Sept. 14 with new episodes premiering each week.