[Warning: This story contains spoilers from this Sunday's The Leftovers season finale, "The Prodigal Son Returns."]

Tensions exploded between the citizens of Mapleton and the Guilty Remnant on Sunday's first season finale of The Leftovers.

The episode is the third directorial effort of the series for Mimi Leder, who shot one of the show's most shocking installments — the stoning murder of Gladys (Marceline Hugot) — and the introduction of Garvey Sr. (Scott Glenn) and his National Geographic magazine, a storyline on which the finale touched in Garvey's (Justin Theroux) fascinating dream sequence.

It had its fair share of metaphysical and character-driven questions: What was Garvey's wish, and did Holy Wayne (Paterson Joseph) truly grant it? How did Laurie (Amy Brenneman) and Tom (Chris Zylka) happen to end up in the same park? What's the effect of the Bible verse on Garvey and the baby on Nora (Carrie Coon)? What's with the dog?

Leder has answers (except when it comes to the dog; she says, "you just have to read into it yourself what you bring to it"). But she says her finale's themes are those that run throughout the entire first run of the ambitious HBO drama, which will return for a second season. "I think there's a common thread of anger, despair, grief, loss — of, is there hope for humanity?" she tells The Hollywood Reporter.

The director explains her episodes and discusses the season with THR.

What was hardest to get right in the finale?

One of the scenes that was so very hard to achieve, especially because it was shot in two days, was the burning down of the cul-de-sac of the GR's houses. It was an intense, difficult scene to shoot. We're not an action show, so my approach to it was to try to get into the head of Kevin Garvey — to follow him on this journey of seeing what has happened to his town, seeing it through his eyes. He's discovering that the GR has done the unthinkable, has made them remember, after he's gone through quite a confession himself.

That was a very difficult sequence to shoot. It had a lot of visuals and effects, like the fire. It was very emotional, seeing the bodies being thrown on the bonfire and Laurie being thrown out of the house, hearing her voice for the first time in all the episodes except for the flashback.

Were there scenes you thought would be difficult but that came together very naturally?

One of the scenes I feared the most was Nora Durst discovering her family and how that would work, and after the first take, we all just fell apart because it was just so painful to witness and so pure and honest a scream. We took the sound out of it, which made it even more difficult to watch. Just as you think that she's recovering and moving on, you realize that you can never move on, as Holy Wayne says in episode 6 ... "will I forget them?" and he says, "never." And the Guilty Remnant will never let them forget. For Carrie Coon, who is a great discovery and a deeply affecting actress, she went there. She went to the floor literally in seeing her Loved Ones.

Another that was difficult was Justin Theroux's reading of the Bible, in an extraordinarily brilliant performance that went so deep. It was just difficult to modulate not that performance, but the whole episode. You have that scene where he’s deeply affected by the words, and Matt Jamison (Christopher Eccleston) has definitely helped him in the reading of those words. But how far do you go with the tears, when you know you have a scene coming up where he confesses to Matt that he wanted his family gone?

The scene with Wayne was quite beautiful and quite powerful, and we wanted to do it very simply. There was the coincidence of Holy Wayne being in that bathroom, having had a huge effect on Kevin's son's life, and granting Kevin the wish that ultimately comes true, perhaps, in the last moments of the show.

What was he wishing for?

What I told Justin was that he was wishing for a new beginning, a rebirth, to start over. In that moment, when Nora comes to the doorstep to leave the note and leave him and leave Mapleton, leave everything behind, she finds this baby. All she says is, "look what I found," and you can see that in the midst of all this anger, grief, uncertainty and loss, there's hope. There's the possibility of love, the possibility of a new family.

How do Laurie and Tom figure into this new beginning?

In the show's arc, [creators] Damon [Lindelof] and Tom [Perrotta] so brilliantly crafted a closeness between Laurie and Tom. Laurie and Tom were both drawn to cults, they both sought out answers. I think Laurie is at this point very disillusioned by everything she thought she believed in, and Tom in his arc during the series has been disillusioned by Holy Wayne, feeling that perhaps he is the fraud that Wayne himself feels he is. (But perhaps in his moment of death Holy Wayne is not a fraud; perhaps the wish he granted Kevin will come true. We don't know — we'll see.) Their stories are about what we as human beings have the ability to believe in, how deeply we believe things can come true if we will them to.

Laurie and Tom have a very special connection. Kevin married her, fell in love with her and raised Tom as his son, but Laurie and Tom have a special connection. Where she goes at the end is where it all began in the pilot: the memorial park. It was another coincidence — how does he show up and find his mother? I said to him and to her, this is the place where you guys would meet. This is the place where your mom would take you. This was their place. So just when she thinks all is lost, she looks into the water, into the abyss, she turns and sees her son.

He's delivered the baby to Kevin's doorstep, because he was abandoned by his father and Kevin took care of him. He took the baby to the only place he knew the baby would be taken care of.

So in the aftermath of the burning of the GR, Laurie's disillusioned with the group?

In the aftermath, when Laurie is looking at her family again — I was reading some reviews about it, and people thought it was Kevin wanting her back. But it wasn't. It was a moment about, "don't come near us." It was a moment about, "you've hurt us so much."

She's disillusioned and feels the shame of having put her daughter in jeopardy. One of the scenes that was most interesting and most difficult in many ways was the sequence in the house where her daughter (Margaret Qualley) is there and her daughter says, "talk," and she says not, "go away, go home, it's dangerous." She wants to protect her daughter, but she wants to carry out what she has been planning with her group for all these months. The conflict of being the mother and that instinct coming out was a great challenge to her.

Where does this episode leave the GR, in particular Liv Tyler's character Meg?

Liv Tyler has just been an extraordinary force. People see Liv as this very fragile kind of waif, and she's really this strong, tough, powerful woman. I loved shooting her coming out of the house, taking over Patti's (Ann Dowd) role as the leader and filling those shoes.

The GR will never let anyone forget what happened — you can go on with your lives, but you can never move on. They're the realists. So are they a cult, really? It made a lot of sense in many ways. They'd rather live in reality than in denial.

You directed the series' other most devastating moment of violence against the cult, the stoning of Gladys. How did you go shoot that scene?

When I read it, I thought, "Oh my god, how am I going to shoot a stoning? How am I going to do one of the show's most shocking scenes?"

I wanted everything to be very still before they abduct her, and then I wanted everything to be so wild that you could barely see, just the struggling of being dragged through the woods and tied up and having this vow of silence. I shot it very simply in terms of camera angles. Once we got there, we needed to be still so that we could feel the effects of the stones hitting her face and destroying her life and the tragedy of her begging for her life even though she martyred herself. It was a very powerful thing to shoot, very frightening to shoot.

In your episode centered on Kevin's father, what's your sense of the elder Garvey's mental state? Is he crazy?

My interpretation is that he is hearing voices and that he's not crazy. I think he snapped after the departure, the voices really do come and talk to him. That's why I did the shot of his reflection in the window — who's he talking to? He's definitely talking to somebody. He definitely hears the voices, the voices are telling him what's important, and he tells his son to listen. This is Damon's brilliant crafting — in episode nine, we go back and we see Garvey Sr. tell his son, "this is it. This is your purpose in life. You need to accept it. There isn't any more than this." In that moment, your mind will hopefully go back to this episode seven. It's part of Kevin's arc, finding out what is his purpose in this life.

Has he found it?

I think he's still discovering it. I think he's just, in this finale, confessing to what happened at the moment of departure and what he was wishing for. He was wanting his family gone, and he feels the guilt. He is still looking for his purpose.

Email: Austin.Siegemund-Broka@THR.com

Twitter: @Asiegemundbroka