CASSANDRA S DREAM tells the story of Ian (Ewan McGregor) and his younger brother Terry (Colin Farrell). Despite their economic hardship, both acquire a second-hand sailboat called 'Cassandra s Dream', with the idea of ??conditioning and sailing on the weekends. Ian meets attractive Angela (Hayley Atwell) a young actress who has just arrived in London in search of a future of success in the world of interpretation, and immediately feels fascinated by her. On the other hand, the weakness of Terry by the game, will cause both to confluence in an impasse in which his financial situation will be extremely delicate. The appearance of his uncle Howard (Tom Wilkinson), newcomer from the United States and with a past apparently full of economic success, is a relief for the economy of the brothers. But everything has a price. Tom will force them to break the law, test their morality, and provoke a series of events that will lead to unexpected consequences.