Phantom Justice (1924)

On a visit to the dentist, Kingsley, an attorney, is confronted by a well-known criminal, who asks him to defend "Goldie" Harper, a girl accused of killing a man whose body has not been found. The attorney agrees to take the case, and Goldie is released. Eventually, police detectives discover the dead man's body in Kingsley's back yard. This eventuality causes the attorney to awaken: he finds himself in the dentist's office--and realizes it was all a dream.