Revenge in the House of Usher

Dr. Alan Harker receives an invitation and arrives at the house of his former professor at the Prague University, Roderic Usher, who lives with his housekeeper Helen in an old castle. Dr. Usher is insane, living with ghosts, and invites his former student Harker to proceed with his research. He tells to Harker that when his daughter Melissa died many years ago, he had developed a means to reanimate her using the blood of prostitutes. Along many years, Dr. Usher and his assistant Morpho kidnapped and killed many young women to keep Melissa alive. But when Harker meets Dr. Seward, who is the doctor of Dr. Usher, he explains that Dr. Usher is delusional. What is the truth about Dr. Usher and his secret?