Rick (Humphrey Bogart), an exiled American fighter, runs the best bar in Casablanca during the start of the Second World War. At this time, France owns Casablanca free from German rule although all sorts of nationalities can be found within the town. Casablanca is notoriously difficult to get away from due to the need for a visa from the police captain Renault.
Externally, Rick is neutral to everyone although he is able to perform subtle favours for those who he feels deserves them. He finds himself in possession of two illegal visas marked for the attention of the Czech underground leader Victor Lazslo (Paul Henreid) and, as Rick looks to pass on the visas immediately, his mind is changed as he meets his old flame (Ingrid Bergman) who is now Lazslo's wife, Isla Lund.
Rick must choose between allowing Lazslo to escape and continue his fight for freedom or keep the passes and the woman he once loved close by.