Random Harvest is based on a story of a World War I soldier Charles Rainer (Ronald Colman) who had lost his memory and was impounded in a sanitarium. He had no identity, nowhere to go and no next of kin. He wandered into the streets and stumbled into a pub where entertainer Paula (Greer Garson) befriended and took him home. Charles and Paula fell in love with each other and lived happily for years and Charles later discovered he had a talent for writing. While selling his stories, he was hit by a speeding car. When he recovered from the accident he regained full memory of his true identity from before while losing memory of the latest event including his marriage to Paula. Charles resumed his aristocratic life while Paula takes a fictitious identity to become his secretary in the hope that one day he will recognize her as his wife. In a desperate move to be close to her husband she seeks the help of psychiatrist Dr. Jonathan Benet (Philip Dorn) who advised Paula that revealing her true identity may be fatal shock for her husband.