This film marked the end of the "serious" Universal Monsters era (Abbott and Costello meet up with the monsters later in "Abbott and Costello Meet Frankentstein"). It was a somewhat desparate, yet fun attempt to revive the classic monsters of the Wolf Man, Frankenstein's monster, and Dracula one "last" time.
I say desparate, because in the previous film, "House of Frankenstein," both Dracula and the Wolf Man are killed according to how the vampire and werewolf legends say they should be (Dracula by the sunlight, and the wolf man by a silver bullet). Yet somehow they return in House of Dracula with no explanation. This movie could have played as a kind of prequel to House of Frankenstein if the Frankenstein monster plot wouldn't be continuing chronologically into House of Dracula from House of Frankenstein, and if the wolf man didn't get cured. Then there'd be no plot holes. But since this is not the case, the plots of Dracula and the Wolf Man make no sense.
However, ignoring these plot holes, House of Dracula is a classic atmospheric horror film that's fun to watch. It has many high points. Especially seeing the wolf man get cured. I know I just said that this shouldn't have been included, but it was nice to actually see him get cured after all this time. And the scene with the lady playing "Moonlight Senada," on the piano then all of a sudden playing a haunting melody when under Dracula's spell was very eerie. Dr. Edleman's transformation into the "Dr. Jekyl/Mr. Hyde" type character was also done very well.
And it's great to see Dracula, Frankenstein, and the Wolf Man together, one "last" time.
*** out of ****