Haunted by the memory of Walter Holderlin, a soldier he killed during World War I, French musician Paul Renard (Phillips Holmes) confesses to a priest (Frank Sheridan), who grants him absolution       Using the address on a letter he found on the dead man's body, Paul then travels to Germany to find his family      　　As anti-French sentiment continues to permeate Germany, Dr       Holderlin (Lionel Barrymore) initially refuses to welcome Paul into his home, but changes his mind when his son's fiancée Elsa identifies him as the man who has been leaving flowers on Walter's grave       Rather than reveal the real connection between them, Paul tells the Holderlin family he was a friend of their son, who attended the same musical conservatory he did      　　Although the hostile townspeople and local gossips disapprove, the Holderlins befriend Paul, who finds himself falling in love with Elsa (Nancy Carroll)       When she shows Paul her former fiancé's bedroom, he becomes distraught and tells her the truth       She convinces him not to confess to Walter's parents, who have embraced him as their second son, and Paul agrees to forego easing his conscience and stays with his adopted family       Dr       Holderlin presents Walter's violin to Paul, who plays it while Elsa accompanies him on the piano      　　The film's original title, The Man I Killed, was changed to The Fifth Commandment to avoid giving wrong impressions in the minds of the public about the character of the story       It ultimately was released as Broken Lullaby