Note: This story contains spoilers from “American Horror Story: Murder House” and “Apocalypse”

One of the queens of “American Horror Story” has returned for “13.” Jessica Lange’s biting and and iconic Constance Langdon appeared in the first three episodes of this latest season, and seems to play a vital role in the installment’s hellish mystery.

One of protagonists of Season 1, Constance has been part of “AHS” since the beginning. She also played a major role in the “Apocalypse” season of the show. But considering the fact that it’s been 15 years since she was introduced, fans will be forgiven for forgetting the nuances of this grieving mother’s story. Here’s what you may have forgotten.

Did Constance die in “American Horror Story”?

Yes, but it’s complicated.

When Constance first appears in “Apocalypse,” she gets into a spat with the maid of Murder House, Moira (France Conroy and Alexandra Breckenridge). Moira shoots back that Constance took “took the coward’s way out,” implying that she killed herself and is bound to Murder House alongside her late children.

Michael Langdon (Cody Fern), aka the Antichrist, was the reason Constance took her own life. While Constance was raising him, he kept leaving her “presents,” a morbid habit that started with dead rats and escalated to murder as he got older. He also became increasingly violent toward Constance, threatening to kill her. Constance admits in “Apocalypse” that raising Michael “shattered her” and that she kicked him out after finding a murdered priest in his bedroom. She ended her own life so that she could be free of Michael and spend the rest of eternity with her deceased children.

But this is where the timeline gets a little murky. Constance tells this story to Madison Montgomery (Emma Roberts) and Behold Chablis (Billy Porter) in 2017. However, “Apocalypse” ends with the witch Mallory Redmond (Billie Lourd) going back in time to the year 2015 and running over Michael with a Range Rover. Though the dying Michael begs his grandmother to pull his body onto the lawn of Murder House — an action that would ensure he becomes a ghost — Constance kicks him and leaves, cementing Michael’s death.

Mallory’s actions mean that the “Apocalypse” timeline was erased. But, based on “13” so far, it seems as though no matter the timeline, Constance is still linked to hell.

Constance Langdon’s backstory, explained

Constance Langdon may not have been the greatest mother, but she is one of the most iconic when it comes to “American Horror Story.”

Born and raised in Virginia, Constance moved to Los Angeles to pursue her dream of being an actress, a dream that fell flat partially due to her refusal to do nudity. In 1983, she found her husband Hugo (Eric Close) having sex with the maid Moira, an encounter that Constance believed to be consensual even though it was rape. Constance murdered them both, shooting Moira through the eye. Afterward, she fell into a deep depression, which led to her neglecting her children.

Constance had four children — Rose (Raina Matheson), Beauregard, Tate (Evan Peters) and Adelaide (Jaime Brewer). All of them reached tragic ends. Rose died as a young child. It’s implied that she was either born without eyes or that her eyes were gouged out, which led to an infection and her eventual death. Beauregard (Sam Kinsey) was a sweet child who was born deformed. He was kept chained in the attic of Murder House until Constance had Larry Harvey (Denis O’Hare) smother him to death with a pillow — a murder Constance has refused to admit was her fault. Though Tate was the only one of Constance’s children without a physical or mental condition, he was a sociopathic and troubled young man. In 1994, he shot up his school, a tragedy that led to Tate murdering 15 of his classmates before a SWAT team killed him in his home. Tate was dead throughout “Murder House,” which is a major plot twist in the first season.

The only one of Constance’s children who was alive at the beginning of “Murder House” was Adelaide, or Addy. A well-meaning and sweet girl, Addy was born with Down syndrome and has dreams of one day becoming a “pretty girl.” She was ultimately killed in a hit and run outside of the Murder House. Though Constance tried to drag her to the property before her death, she failed, meaning that Addy died rather than returning as one of Murder House’s ghosts. Later, Constance contacted Addy via medium and learned that Addy was happy to not be bound to the house.

Because Constance was such a cold and distant mother, Tate’s ghost developed a close relationship with Nora Montgomery (Lily Rabe), the wife of the first owner of Murder House who became a surrogate mother of sorts to Tate. Both Tate and Nora were ghosts when their relationship developed. The one thing that Nora wanted more than anything else was a baby of her own, which Tate decided to give her. He donned a gimp suit and walked into the bedroom of Vivien Harmon (Connie Britton), the living owner of the house in Season 1. Vivien slept with Tate, believing that he was her husband. Vivien became pregnant with twins after this rape, with one child fathered by her husband and the other fathered by Tate. Jeffrey Harmon died shortly after his birth, but Michael Langdon survived and was raised by Constance.

How is Constance alive now?

In the third episode of “13,” Constance is celebrating the pagan holiday Rauhnacht 13 days after Christmas. Kai Anderson (Peters), Winter Anderson (Lourd) and Tate explain that, during Rauhnacht, the veil between Earth and the spirit world is at its thinnest and that demons wander freely through the gates of hell.

Whatever’s happening in “13,” Constance seems to be leading the charge. She assures Elizabeth Short (Mena Suvari), aka the Black Dahlia, that “very soon you will be among 13 leading ladies all as legendary as you are.”

“American Horror Story: 13” releases new episodes Thursdays on FX and Hulu.