A salty dog of a sailor Thomas "Tommy" Wake (Willem Dafoe) and an apprentice lighthouse keeper Thomas Howard (Robert Pattinson) land on a remote barren rock in the ocean for a one-month rotation as lighthouse keepers.

Their jobs are straightforward. They must keep the light in the lighthouse lit and the foghorn sounding to guide ships through the treacherous waters off the coast of Nova Scotia in 1890.

The remoteness of the island, the laborious nature of the work stoking the engine that provides the power to run the foghorn and the lighthouse, the extreme weather conditions and the mental strain placed on each man are the true challenges of their work.

This is not a romanticised tale of exotic locations and character-building adventures.

Both Thomases initially assume their roles and go about their duties with little conversation or distractions.

As a seafaring man who has been forced to perform land-based duties due to a leg injury, Tommy assumes the senior role, much to Howard's annoyance. Tommy is far too secretive about what he does when on-duty throughout the nightshift, and the reports he is writing about Howard that he keeps locked in a cabinet.

Gradually, the strain of their duties, their excessive consumption of alcohol and their personal clashes see them become unsettled and eventually unhinged as the weather turns vicious.

You are unsure if the dead sailors and alluring mermaids they see are an illusion brought on by their isolation or an outward expression of their inner turmoil.

The black and white photography enhances the environmental hardships and each man's physical appearance. The constrained format and sound design compound the bleak living conditions.

The dialogue, especially from Tommy's mouth, is like a living sea shanty.

The Lighthouse depicts the descent into madness of two men isolated on a barren rock in the ocean while the film itself descends into strangeness. That's not necessarily a reason to avoid the film.

But you may wish to consider its brutal depiction of mental decline, and the curious mix of folk tale and mythology centered on tales of ancient sea gods and mermaids and seagulls that bear the souls of dead sailors.

Sounds weird? That's because it is.

Films that provide challenges for the audience are worth seeing if only to provide a contrast of style and presentation with mainstream cinema.

Having said that, The Lighthouse offers physically and psychologically disturbing scenes that will challenge and confront any audience.