She is portrayed as a resilient and fiercely protective mother to her son Will, who mysteriously disappears in the town of Hawkins, Indiana.
Joyce is characterized as a determined, resourceful, and deeply emotional person, willing to go to great lengths to find her son, even if it means confronting supernatural forces.
[7] Ryder continued to play Joyce in season 4 of the show, having a crucial part in the segments set in Soviet Russia.
In season 1, Joyce Byers is depicted as a kind, caring, and sometimes frazzled single mother working at a general store in downtown Hawkins, who lives with her sons Jonathan and Will.
Hopper later becomes convinced Will is missing after finding his bicycle abandoned in a wooded area the children call Mirkwood.
She is dismissed as crazy when she begins to see faded visions of Will through the wall and thinks that he is communicating with her by manipulating lights around the house, but she remains steadfast in her faith.
After being apprehended and interrogated, Joyce and Hopper are permitted under Dr. Brenner's orders to venture into the Upside Down with protective suits.
Still traumatized from the events of season 1, Joyce is shown to be overprotective of her son Will, no longer letting him bike around town by himself.
Joyce grows increasingly worried about Will, who begins having frequent "episodes" where he experiences realistic visions of the Upside Down.
After Joyce promises Will that she will not take him to the suspicious Dr. Owens, Will says that he does not remember anything other than the shadowy figure he had been drawing previously, which the children call the Mind Flayer.
Joyce notes that some of the lines connect, which leads her and Hopper to figure out that the drawings form a map of interconnecting tunnels under Hawkins.
There, creatures dubbed "Demodogs" assault the facility, and Bob offers to reactivate the on-site power in order to facilitate an evacuation.
Angered by Bob's death and desperate for an end to Will's ordeal, Joyce burns the shadow monster out of Will while Mike lures the Demodogs away from the gate so Eleven can close it.
They learn that the Russians opened the portal to the Upside Down using the machine, and Joyce and Hopper decide to call the CIA.
She calls Murray, who suggests the doll might have been sent to her by the KGB, who want to capture her for her role in destroying the Soviets' secret operations under Starcourt Mall in season 3.
She realizes the doll is broken and finds a note inside it, which tells her that Hopper is still alive and provides a phone number.
Looking for a way out, Joyce, Hopper, Murray, Enzo and Yuri find Demodogs held captive around the prison, seemingly as subjects in scientific experiments.
Recalling the Upside Down creatures' hive mind, Joyce deduces that they can help their kids by killing the Demogorgon and the Demodogs they saw, so they decide to re-enter the prison.
Back at the prison, Hopper gets attacked by Demodogs, triggering a flashback for Joyce to her boyfriend Bob Newby's death at Hawkins Lab.
She attends HHS with many familiar characters such as Jim Hopper, Bob Newby, Ted Wheeler, and Henry Creel.
After numerous cast and crew members have their animals killed under mysterious circumstances, Joyce, Hopper, and Bob attempt to uncover who is behind the heinous acts.