The name Donald Crowhurst may not mean much to many.
But The Theory of Everything's director is aiming to change that with this intriguingly melancholy and cautionary tale of hubris.
A failing inventor and salesman in the 1960s, a contemplative Crowhurst (a sincere Firth) decides to take on the 1968 Sunday Times Golden Globe Race to prove something to himself and to leave a legacy.
The round-the-globe race would see the amateur sailor granted fame and his family and help boost their family out of the financial mire.
So, with a not sea-worthy boat and a headful of doubt, as well as saddled with debt, Crowhurst sets out to fulfill his burning desire to do something with his life.
And along with a publicist plotting everything on land (a bullish Thewlis), Crowhurst finds the pressure building...
The thing about The Mercy is, much like Robert Redford's flashier All Is Lost, it's essentially all about the demons of a man left at the mercy of the elements and with only his own thoughts to spend time with.
Whereas All Is Lost was a little more of a traditional film, complete with danger, The Mercy's melancholy is the one over-riding element, as it washes over in the final back half of the film.
The tragic atmosphere's greatly helped by Marsh's sound team, who amplify the creaking of the mast, the lapping of the sea and the constant drip of water to maximum effect, building a soundscape which goes some way to giving an insight into Crowhurst's descending state of mind.
Whereas the first third of the relatively short film devotes an inordinate amount of time to telling backstory and simply presenting it with clunking ease, the rest of the film allows the actors the time to shine.
Particularly Weisz, whose initial appearances as a supportive wife are thankless at best - and superfluous at worst.
Aside from one awkward CGI presentation of great swells which appears to be cast offs from Mark Wahlberg's The Perfect Storm, the simplicity of the presentation of life on the sea gives the ever-reliable and always relatable Firth the chance to offer a subtle and nuanced turn as the woefully inept Crowhurst starts to face the reality of his situation.
Despite what Thewlis' PR person bellows early on, ("it's a story of derring do, waiting to be told,") The Mercy is not that kind of film.
Maudlin and with some narrative edges that will require leaps if you're not familiar with the events that transpired for Crowhurst, it's a once over lightly psychological piece that skirts with the psyche of sailing rather than fully diving deeply in. Something which becomes deeply more evident in the film's final straight.
The Mercy never quite achieves the insight into Crowhurst that perhaps it's aiming for, but in translating the smaller details to the bigger screen, it's a little more successful than you'd expect, but also a little more disappointing if you're after something more substantial as it strays from its course.
