Watching Cecilia is their housekeeper's son Robbie Turner (James McAvoy), a childhood friend who, along with Briony's sister, has recently graduated from Cambridge.
By the end of that day the lives of all three will have been changed forever. Robbie and Cecilia will have crossed a boundary they had never before dared to approach and will have become victims of the younger girl's scheming imagination, and Briony will have committed a dreadful crime, the guilt of which will colour her entire life.

REVIEW: When you read critical acclaim about a movie these days, the inclination is almost to greet it with a deep degree of scepticism.
More than occasionally what the critics hail as truly great lacks the real punch and entertainment that we the punters actually crave.
Thankfully with the British-made Atonement, which was released to almost universal acclaim on our cinema screens in 2007, the hype is more than justified.
Based on the novel by Ian McEwan, which was equally lauded in literary circles, Atonement sees the beautiful Kiera Knightley reunited with director, Joe Wright, who she worked alongside for the film adaptation of Pride and Prejudice.
Almost from the moment this heart rending story begins, we are gripped by the combination of Wright's superb direction, some stunning photography and terrific performances from Knightley and James McAvoy, who has never produced a better performance than in his role as the housekeeper's son Robbie Turner.
In the searing heat of 1935, the romance of Knightley and McAvoy is initially slow burning, with Knightley playing the role of the haughty English girl perfectly.
Wright initially keeps us waiting patiently before the couple's feelings explode in a sexually charged and emotional love scene.
We can almost feel the real passion between the pair but unfortunately for the two lovers, they have been seen by Cecilia's 13-year-old sister Briony.
Her actions that evening have the darkest of repercussions and we are taken on a rollercoaster ride all the way to the beaches of Dunkirk and the horrors of the Second World War.

VERDICT: You won't be disappointed because Atonement delivers on just about every scale. Best film, not surprisingly at the BAFTAs, Oscar recognition wouldn't have flattered Atonement either.

All DVDs courtesy of Bridge Video, 149 Bridge Street, Portadown, (028) 38 334185 (opening times: Monday to Friday 4-10 o'clock, Saturday 1-10 o'clock).