How does Jacobs create suspense and surprise at the end with the banging and opening of the door?

Monkey's Paw certainly explores the horror gothic genre. The White's are a seemingly normal family cast into the darkness of the extraordinary or supernatural. Tension is built up through the story. Subsequent wishes that are made to fix the dark result of their previous wish. The knock at the door is the culmination of the ill-begotten wishes. The author provides all the trappings of a gothic climax with a storm and crashing lightening. The knock on the door is even a prelude to some zombie action!.