Does the Masque of the Red Death have a resolution?Is it when the clock stops or when they die? I am not sure what the resolution and denouement is.

Yes, I believe that there was a resolution and denouncement in Poe's "The Masque of the Red Death." Prince Prospero's arrogance and desire to prove he was not going to be a victim of the fear of the plague brings about the Masque.  All of the people in attendance are determined that death can not touch them.  When the clock strikes 12 they notice the

"masked figure,’’ who is ‘‘tall and gaunt, and shrouded from head to foot in the habiliments of the grave,’’ and looks like the corpse of a body afflicted by the Red Death, its face ‘‘besprinkled with the scarlet horror.’’ Prince Prospero orders that the figure be unmasked and hanged at dawn, but his guests refuse to unmask him. The figure then retreats through all seven rooms of the abbey, pursued by Prince Prospero. When the figure reaches the seventh room, it turns to face the Prince, who falls instantly to his death. When the guests rush to seize the figure, they find that, beneath the corpselike costume, there is no "tangible form.'' The masked figure turns out to be The Red Death itself. It had crept into the sealed abbey "like a thief in the night.'' The last line of the story indicates that the Red Death has triumphed over life: "And Darkness and Decay and the Red Death held illimitable dominion over all.’’

The death of Prince Prospero and all of his guests is the resolution to the story and as in all great stories, in the end the lights go out.