When the group investigated further, Nancy and Jonathan discovered a blood stain on a carpet, causing them to remember Tom having a bandage on his forehead when he fired them. Before they could get a response, they were confronted by Hatch, who escorted them out and tried to have them arrested upon learning of their fake identities. After sternly warning Jason to back off, she and the others managed to get everything they needed and drove away before Jason and his friends grew too suspicious.

Sometime later, Nancy attended the funeral for Barbara which was held after the revelations forced Hawkins Lab to acknowledge their involvement in the coverup of Barb's death after Murray revealed the evidence Nancy and Jonathan presented to him. The teens eventually all gathered in the mansion's attic and detected strange activity upon noticing the lights flickering on and off.

A desperate Victor tried to take his children away from the house, only to be taken once more into a memory of his time as a soldier.

Suddenly, their flashlights exploded one by one before the bulb providing the light to the attic also exploded and plunged the whole space into darkness.When Nancy tried to justify her and Jonathan's actions, she was interrupted by Tom who told them that Doris was in a bad state and that her family was furious. As Nancy entered her senior year of high school, she started to take Mike to school with her as he had become a freshman in high school while joining the school newspaper, The Weekly Streak.

As they danced, she told him that girls that age are “dumb”, and assured him that in a couple of years he’d “drive them nuts. However, everything changed when Barb vanished without a trace, prompting Nancy to team up with loner Jonathan Byers, whose younger brother Will had also vanished.Fearing something terrible had happened to Barb and nobody was listening to her, Nancy began taking matters into her own hands. The moment was interrupted by Robin, who warned them that they had found the house, and the trio soon noticed Erica's light in the playground. After Dustin noted how Max's trance was similar to the state Chrissy was in before she died from Eddie's descriptions, Nancy and the others heard Max state that her trance was not the only thing they should be concerned about. When making a sensory deprivation tank at Hawkins Middle, Mike was impressed when Nancy broke the lock to the school shed to get supplies. Although she found Will (barely) alive, she also discovered that Barb had been killed by the Monster.

However, the reunion was interrupted when all of them witnessed dark clouds and unusual white spores descending the sky, prompting them to head to Weathertrop hill, where they witnessed a field of flowers slowly dying. When Dustin's compass began going haywire, Nancy heard Dustin strange electromagnetic activity was causing his compass to malfunction, which he revealed the possibility of a new gate being opened somewhere nearby. She also disobeyed and lied to her mother, telling Karen that she and Barbara were going to help look for Will Byers, when they were in fact going to a party at Steve Harrington's house. However, when Nancy started dating him, Barb became concerned for Nancy as Steve and his friends started to influence her.As they walked down the cells in the basement of the facility, the girls listened as Hatch explained that each person had its favorite kind of music, which could reach inner parts of the brain that words could not. Just before the monster could kill her, Nancy was saved when Mike, El, Max, Lucas, and Will arrived where El used her powers to fight the monster and push it out of a window. However, after entering a relationship with Steve she became more rebellious, lying and participating in activities she most likely wouldn't have done otherwise. When she was looking for the missing Barb, she boldly entered a portal to another dimension in an attempt to save her friend. Upon looking closely at the drawings of Vecna's mental realm made by Max Mayfield, Nancy was able to put them together and deduce that a fragmented version of the Creel family house was part of Vecna's mindscape, giving the Party and their allies another clue that led them closer to discovering Vecna's true identity as Henry Creel.