Who is dirk Jackson in the hidden staircase?

Dirk Jackson is a character from "The Hidden Staircase," which is part of the Nancy Drew Mystery Stories series. He is introduced as a young man who assists Nancy Drew in her investigation of the mysterious happenings at the mansion known as the Hollow. Dirk provides support and insight, helping Nancy navigate the challenges she faces while uncovering the truth behind the hidden staircase and its secrets. His character adds a layer of camaraderie and teamwork to the story.