After the American newspaper tycoon Kane (Orson Welles) died in the Sanando Manor, leaving behind the "last words" of "rose bud", a young reporter was commissioned by the media to investigate the meaning of these four words. He then visited Kane's colleagues and friends during his lifetime. From the newspaper chairman Bernstein, he learned about Kane's rise to fame and how he created public opinion to get the United States involved in the war in 1897. From Leland's story, he also learned about Kane's marriage to Emily, the niece of the US president, his complicated relationship with his second wife (singer) Susan, and his failure in the presidential election. After listening to a lot of stories, the reporter went to the library to check out detailed information about Kane. He also learned more about Kane, his experiences in his youth and his relationship with his mother. However, he still didn't know the meaning of the four words "rose bud".