Warning: Spoilers ahead for "The Leftovers" season three premiere.

The auspicious season three premiere of "The Leftovers" aired on Easter Sunday — and once again, the season began with a cold open.

Though there were hints throughout the opening sequence that pointed towards the significance of the people featured, INSIDER spoke with the episode's director Mimi Leder and the co-creator of the series, Damon Lindelof, to better understand the meaning behind the powerful scene.

The episode began by showing a family preparing for an event akin to the Rapture. There is no dialogue throughout, but instead a Christian rock song titled "I Wish We'd All Been Ready" plays over the scenes.

We see the family give away their belongings, dress in white robes, and climb up to their roof to wait.

Nothing happens.

The Millerites stood on the roof of their house, waiting to be brought to heaven. HBO

Then the family goes to a church, where their religious leader circles a new date on a chalkboard — January 21, 1844. The husband, wife, and son all smile, and repeat the process of preparing and going to the roof.

Nothing happens.

When the religious leader gives yet another date, the husband in the family loses faith but the wife's belief remains. He takes their son, leaving his wife to perform the ritual by herself again.

Nothing happens.

Clearly distraught and confused, we see the woman walk back through her village and into the church again. She lays down next to another person, and the camera pans over their white-robed bodies until suddenly we are seeing modern day members of the Guilty Remnant (GR) sleeping, all dressed in white.

"The Leftovers" executive producer Mimi Leder was also the director for this episode, and INSIDER spoke with her to learn more about that opening sequence.

The scene is based on a religious sect called Millerism

"It was really fun shooting the Millerite sequence," Leder said. "Just shooting a scene wordless and trying to tell the story of a similar cult to the GR — a cult that wanted to be Raptured and join the others — it was challenging."

Leder called the people shown in the opening sequence "Millerites" — which are the followers of a real religious sect founded in New York in the 1800s called Millerism. A farmer named William Miller came up with a new way to interpret the Book of Revelation, and did mathematical calculations to determine when the Second Coming of Christ would occur and worthy believers would be carried into heaven.

But Leder said that the people shown in "The Leftovers" were meant to represent a group of Millerites who didn't live in New York, but instead in Australia. Millerism spread around the globe thanks to Miller's inventive use of the printing press and other technologies available at the time. In "The Leftovers," we see the Millerites using messenger birds.

"They called their time 'The Great Disappointment,'" Leder Said. "They were a national movement from 1840 onward, and they actually were [started] in New York, but our group was in Adelaide."

The Great Disappointment was actually written on a chalkboard in "The Leftovers" scene. This is what the Millerites called this period of time when they realized Miller had been wrong.

This church was apparently in Adelaide, Australia. HBO

We know that Kevin Garvey Sr. has been in Australia since the end of season one, so perhaps the choice to depict a group of Millerites in Adelaide will be significant later down the road in season three. For now, Millerism serves as a poignant parallel for the GR.

"They stood on roofs and gave away their belongings and waited for the Rapture that didn't come," Leder said. "The woman and the family were giving up their belongings, all their stuff was in a little baby crib (which could have been a crib of a child they lost). We were trying to draw parallels to the GR, who also wore white and were left behind, were the leftovers."

We asked Leder if she thought this meant the GR have an underlying belief that another Sudden Departure will happen, and that they want to be Departed, too.

Meg, Patti, and Laurie were all in the GR in season one. HBO

"I don't think our GR feels that," Leder said. "Our GR feels that there is no family. I don't think our GR is waiting to be Departed. I think they do want to die, you know? I think they want to end their lives. That's what I think."

Some of the GR have that wish granted. The Millerite sequence moves into a scene in Jarden where Evie and Meg were waiting inside the welcome center with their other GR members. Evie hears a disturbance and goes outside only to see an airplane drop a bomb on the center, killing Evie and every other GR member in the building.

How the opening connects to season three's theme

INSIDER also spoke with Damon Lindelof, co-creator and showrunner of "The Leftovers," about the opening scene and how it relates to the overall theme for season three.

"We're not being ambiguous for ambiguity's sake," Lindelof said. "We have a very specific intention. I do think that by the end of the first episode of the show, it's no secret that we told you a story about a group of people who clearly thought that the world was going to end on a specific date and then it didn't, and what the consequences are of that belief system failing them."

Season three jumped forward in time by three years, making it just weeks away from the seventh anniversary of the Sudden Departure. Clearly tensions are rising, and religious believers think that the seven-year marker has larger connotations due to the frequent appearance of the number seven in the Bible.

Mimi Leder on set of "The Leftovers" season three. Van Redin/HBO

"By episode's end, you understand that a good portion of the world is anticipating what is going to happen on the seven-year anniversary of the Sudden Departure," Lindelof said. "It's hard not to think about that circled date on that chalkboard in connecting those dots."

Why Leder and Lindelof have faith in their audience

"The Leftovers" also did a cold open for season two, which showed a cave woman who undergoes her own set of traumas that had parallels to the Sudden Departure. By the episode's end, the audience realized that the place where that cave woman lived was Jarden, Texas — now known as Miracle because it was the only place in the world where no one Departed. The opening sequence set the tone for the whole season, showing that geographical locations can be considered special and draw religious devotion.

"The inspiration for both the way that we open season two and season three was the way that the Coen brothers opened 'A Serious Man,'" Lindelof said. "They have this crazy prologue about a dibbuk that's taking place some place in eastern Europe in an undefined period of time, the early 20th century perhaps. Then there's no explanation as to why they did that. There's a thematic explanation if you want to have conversations with your buddies about why you think they did it, but the Coen brothers have never given an interview where they're like, 'This is why we did it.'"

"I want to have faith in the storytelling and not completely and totally demystify the more 'fanciful departures' from traditional storytelling that we engage in and say, 'In case you didn't get it, here's what we want you to get now,'" Lindelof said.

Mimi Leder, though she did reveal the Millerite backstory to INSIDER, also mentioned why the opening withheld a specific identification of Millerism from the viewers at home.

"I think you don't want to tell an audience everything — you want them to feel it," Leder said.

The second episode of "The Leftovers" final season premieres Sunday, April 23.