Question: Gemma Arterton played the lead role in what movie based on the 2009 novel "Their Finest Hour and a Half"?

Context paragraphs:
Finest Hour: The Best of Gavin DeGraw: Finest Hour: The Best of Gavin DeGraw is a compilation album by American singer-songwriter Gavin DeGraw.  It was released on October 17, 2014 by RCA Records.  On August 14, 2014 RCA Records announced the release of Gavin DeGraw's first greatest hits album, "Finest Hour".  It contains songs from all his studio albums except "Free" (2009).  It also includes the two new tracks "You Got Me" and "Fire".  According to the press release a new song titled "Not Our Fault", written by DeGraw, Jake Gosling, Chris Leonard, and Harry Styles, was intended to be included on the album but did not make the final track listing.

The History of Love (film): The History of Love is a 2016 internationally co-produced romantic drama film directed by Radu Mihăileanu and written by Mihăileanu and Marcia Romano, based on the 2005 novel of the same name by Nicole Krauss.  The film stars Derek Jacobi, Sophie Nélisse, Gemma Arterton and Elliott Gould.

Their Finest: Their Finest is a 2016 British war comedy-drama film directed by Lone Scherfig and written by Gaby Chiappe, based on the 2009 novel "Their Finest Hour and a Half" by Lissa Evans.  The film stars Gemma Arterton, Sam Claflin, Bill Nighy, Jack Huston, Jake Lacy, Richard E. Grant, Henry Goodman, Rachael Stirling, Eddie Marsan, Helen McCrory, and Claudia Jessie.  The film tells the story of a British Ministry of Information film team making a morale-boosting film about the Dunkirk evacuation during the Battle of Britain and the London Blitz.

Gemma Arterton: Gemma Christina Arterton (born 2 February 1986) is an English actress.  Arterton made her film debut in the comedy film "St Trinian's" (2007).  Her breakthrough role was in the James Bond film "Quantum of Solace" (2008), playing Bond Girl Strawberry Fields, which won her an Empire Award for Best Newcomer.  She is known for her roles in the fantasy films "Clash of the Titans" (2010), "Prince of Persia: The Sands of Time" (2010), "Byzantium" (2013) and as the character Gretel in "" (2013).  She played Joan in Bernard Shaw's Saint Joan at Donmar Warehouse, December 2016.  She plays the lead role in "Their Finest" (2017).

The Disappearance of Alice Creed: The Disappearance of Alice Creed is a 2009 British neo-noir thriller film about the kidnapping of a young woman by two ex-convicts.  The film is written and directed by J Blakeson and stars Gemma Arterton as the captured Alice Creed, with Martin Compston and Eddie Marsan as Danny and Vic, the kidnappers.  The film was shot on the Isle of Man.

The Girl with All the Gifts (film): The Girl with All the Gifts is a 2016 British post-apocalyptic zombie horror drama film directed by Colm McCarthy and written by M.R. Carey adapted from his novel of the same name.  Starring Gemma Arterton, Paddy Considine, Glenn Close, and Sennia Nanua, the film depicts a dystopian future following a breakdown of society after most of humanity is wiped out by a fungal infection.  The plot focuses on the struggle of a scientist, a teacher, and two soldiers who embark on a journey of survival with a special young girl named Melanie.

Finest Hour (album): Finest Hour is the fourth comedy album by Patton Oswalt.  It was released in 2011 under Comedy Central Records.  It followed the 2009 release "My Weakness Is Strong".  In 2012, "Finest Hour" was nominated for the Grammy Award for Best Comedy Album, which was instead awarded to Louis C.K. for his performance in "Hilarious".

J Blakeson: J Blakeson is an English film director and screenwriter.  His first feature film was "The Disappearance of Alice Creed" (2009), a kidnap thriller starring Gemma Arterton, Martin Compston and Eddie Marsan, which he wrote and directed.

Gemma Bovery (film): Gemma Bovery is a 2014 French-British comedy-drama film based on Posy Simmonds' 1999 graphic novel of the same name.  Directed by Anne Fontaine, the film stars Gemma Arterton, Jason Flemyng, Mel Raido, and Fabrice Luchini.  The film premiered in the Special Presentations section at the Toronto International Film Festival on 6 September 2014.

Tom &amp; Gerri: "Tom & Gerri" is the third episode of British dark comedy anthology series "Inside No. 9".  It premiered on BBC2 on 19 February 2014.  The episode was based on a play that Steve Pemberton and Reece Shearsmith had written while living together prior to the development of their series "The League of Gentlemen".  While the play had originally been around two hours in length, the episode was only half an hour.  "Tom & Gerri" follows a difficult period in the life of Tom (Shearsmith), a primary school teacher and aspiring writer, and his girlfriend Gerri (Gemma Arterton), a struggling actress, after Tom invites the homeless Migg (Pemberton) into his home.  Conleth Hill stars as Stevie, a man worried about the mental health of his friend Tom.  The entire episode takes place inside Tom's flat.

Supporting paragraphs: Gemma Arterton Their Finest
Answer: Their Finest