Son of Dracula is a 1943 American horror film directed by Robert Siodmak his first film for Universal studios with a screenplay based on an original story by his brother Curt. The film stars Lon Chaney, Jr. and his frequent costar Evelyn Ankers. Notably it is the first film where a vampire is actually shown physically transforming into a bat on screen. It is the third in Universal Studios Dracula trilogy, preceded by Dracula and Draculas Daughter, though Dracula appeared in subsequent Universal films teamed with other monsters.
A shocked Frank runs off to Dr. Brewster, who visits Dark Oaks and is welcomed by Alucard and a living Katherine. The couple instruct him that henceforth they will be devoting their days to scientific research and only welcome visitors at night. Frank goes on to the police and confesses to the murder of Katherine. Brewster tries to convince the Sheriff that he saw Katherine alive and that she would be away all day, but the Sheriff insists on searching Dark Oaks. He finds Katherines dead body and has her transferred to the morgue.Meanwhile, Hungarian Professor Lazlo arrives at Brewsters house. Brewster has noticed that Alucard is Dracula spelled backwards and Lazlo suspects vampirism. A local boy brought to Brewsters house confirms this suspicionthere are bite marks on his neck. Later, the Count appears to Brewster and Lazlo but is driven away by a cross. ........
Source: Wikipedia