Atonement

Outline:
In the summer of 1935, a 13-year-old observes a flirtation between a servant's son and her older sister that she childishly misconstrues. Her misunderstanding leads to a terrible crime whose consequences follow them through World War II. Based on the novel by Ian McEwan.

Summary:
The main reason to see this film will most likely be Kiera Knightley, plus the fact that it's based on a well-regarded novel. With that in mind I obviously gave prominence to her character, but James McAvoy is also certainly on a roll as an upcoming star and this could be his breakthrough role. His character is not as prominent, but is looking to camera which draws the eye. I've hinted at the tagline by using it within the artwork, though I don't think any tagline would be a selling point here. This I think this will be a tough sell with its period drama setting, though it could do very well appealing to both the younger demographic because of the cast and the more mature audience brought by the book's pedigree. Supporting cast will certainly help here. The melancholy tone also gives the impression of a serious drama.