

Box office Īs of August 2020, Nancy Drew and the Hidden Staircase grossed $623,088 at the box office, and a further $322,939 with home video sales. In addition, DeGeneres interviewed Lillis on her talk show to promote the film. Pictures released a short clip from the film. On January 18, 2019, DeGeneres announced exclusively that the film would be released in theaters on March 15 she also debuted a trailer.

Emily Bear composed and sings the songs "More than Just a Girl" and "Daylight". The score of the film was composed by Sherri Chung. Principal photography on the film took place that same month in Monroe, Georgia. In June, other casting was announced which included Zoe Renee as George, Mackenzie Graham as Bess, Laura Slade Wiggins as Helen, Sam Trammell as Carson, Linda Lavin as Flora, and Andrea Anders as Hannah, along with Jay DeVon Johnson, Andrew Matthew Welch, Jon Briddell, Josh Daugherty, Evan Castelloe, and Jesse C. On April 20, 2018, it was reported that Sophia Lillis would star in the film adaptation of Nancy Drew and the Hidden Staircase, which would be produced by Ellen DeGeneres, Jeff Kleeman, and Chip Diggins for Warner Bros. Jay DeVon Johnson as Sheriff Marchbanks.The next day at school, Nancy, George, and Bess welcome Helen into their circle of friends, and together they plan their next adventure at the Lilac Inn. Nancy and Helen work together to save Carson and Flora from their captors, who are then arrested by the police.

When Nancy's investigation proved that the house was not haunted, they were forced to use other means to secure the land. It is revealed that Wharton and Nate were working together to sabotage the anti-train movement, and that they intended to force Flora to sell her house so the line could be built through her property.

She and Helen head to Flora's house, where they discover Wharton and Nate holding Carson and Flora hostage. Nancy's friends Bess and George find out that Wharton is also the man who bought the nutmeg used at Flora's house, and Nancy realizes Carson is being kept in the secret passage there. Security footage from the previous night reveals Carson was ambushed and kidnapped by Wharton. They discover that he never checked out, and his cell phone is still in his room. Worried that something has happened to him, Nancy and Helen head to Carson's hotel. Nancy is not convinced, as Carson had told her he would be staying at a hotel. She calls her father's friend Nate, who tells her that Carson's meeting is at a campsite and reception must be spotty. Later, Nancy realizes her father, who is staying out of town on a business trip, has not checked in with her or her aunt Hannah recently. The rest of the strange phenomenon is explained by a rig that emits concentrated nutmeg through the house's air conditioning, which triggers dangerous hallucinations. The secret passage also contains props the intruder used to simulate a haunting, such as a rigged fuse box to manipulate the lights in the house. Nancy and Helen investigate, and they find a secret passage that leads outside, revealing how the "ghost" entered the house. The next day, Nancy believes that someone broke in and tried scaring them out. That night, strange things begin to happen, with lights going out and then exploding, cabinet doors and drawers opening, and a cloaked figure appearing and warning Nancy to give up her mystery. Excited by the mystery, Nancy stays overnight at Flora's home, along with Flora's niece Helen. While performing community service as punishment for a prank on a school bully, Nancy meets Flora, an elderly woman needing help with an apparent haunting in her home. A local thug named Willie Wharton threatens Nancy one night to try to scare her father into backing down. While Nancy struggles to fit in, Carson is active in local politics, fighting the development of a train line through the town. After her mother's death, 16-year-old sleuth Nancy Drew and her father Carson relocate from Chicago to rural River Heights.
