The series finale of "Mare of Easttown" did not disappoint Sunday night, as the murder-mystery drama set and filmed in the Philly suburbs brought twists and turns that many viewers didn't see coming in the final episode.

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But as fans settled in Sunday night to tune into the limited series' seventh episode, chaos ensued for many viewers when HBO Max — WarnerMedia's streaming service — crashed just as the series finale premiered.

This sent fans, including this writer, into an absolute panic, constantly refreshing and restarting their HBO Max apps on their phones, tablets, computers and televisions. The streaming platform was down for about 20-25 minutes before this writer could finally start watching the series finale.

Viewers took to social media with outrage and disgust over not being able to immediately stream the final episode when it dropped at 10 p.m. Sunday.

But despite the experience being a bit delayed Sunday night, the series finale was outstanding — leaving fans like myself stunned over who actually killed Erin McMenamin. Kudos to director/producer Craig Zobel and writer/producer Brad Ingelsby for keeping viewers on their toes and surprised the entire time.

Before Sunday night's finale, we had seven burning questions that we needed answered before the show ended. Below, we'll unpack the final episode of "Mare of Easttown" through the lens of these questions and what answers were provided.

It's at this point where we warn you that spoilers from the series finale are to follow. So if you haven't watched yet, it's probably best that you fire up HBO Max and watch the final episode before reading any further.

Who killed Erin McMenamin?

This was, of course, the biggest question that needed to be answered heading into Sunday night's finale, and the show wasted absolutely no time addressing it. 

But the final answers didn't come as smoothly as we might've thought, so buckle in for the ride.

Within the first few minutes, we are told that it was John Ross who murdered Erin and had an affair with her. We'll dive more into the affair later. 

John said he was at Frank Sheehan's engagement party on the night of Erin's murder. Erin had tried calling him a bunch of times that night and threatened to tell his wife, Lori Ross, everything if John didn't come meet up with Erin at Brandywine Park. 

John said he left the party and drove to Brandywine Park to meet up with Erin. He said that Erin wanted him to pay for their son DJ's ear surgery. John said that he tried to reason with Erin and told her he'd get her the money for the surgery as soon as possible.

But while this conversation was happening, John said that Erin was holding a gun and waving it around, saying that he ruined her life and was going to kill herself in front of him.

John said he tried to wrestle the gun away from Erin, but it went off and hit her in the hand. John said he then panicked and shot her in the face. He then dragged Erin's body into the woods and went back to the party. 

He later called his brother, Billy Ross, to meet him at the park, and they took Erin's body to Sharp's Woods and Creedham Creek. They dropped her body in the woods because Erin had mentioned that she had been there earlier in the night and it would frame one of the teenagers for her murder, according to John.

John said he convinced his wife Lori to lie to Mare Sheehan and say that it was Billy who was behind the murder and affair. But it was revealed later that Billy Ross cooperated with the investigation and would receive parole.

Deacon Mark Burton's charges were also dropped and he was later released from prison. He ends up staying at his parish in Easttown, but doesn't come back for eight months. He says that some have welcomed him back while others haven't.

So it seems like everything is being drawn to a close quite nicely, right? Well, think again.

Mare gets a call from a man by the name of Mr. Carroll. We know of Mr. Carroll as the widower to Betty Carroll, who died earlier in the series, and that he had an affair with Mare's mom Helen, which he made public at his wife's funeral. 

After chatting for a bit, Mr. Carroll shares that a number of things around his house went missing, one of which was a gun. He says he keeps the gun in his shed, but that it was stolen and later returned. When asked what type of gun it is, Mr. Carroll says it's a Colt Detective Special Revolver — the same type that was used to kill Erin.

This makes Mare suspicious, and she asks to see the gun in Mr. Carroll's shed. After Mare sees the gun, Mr. Carroll mentions that two rounds of bullets are missing in the chamber. 

Mare then asks who has access to the shed, to which Mr. Carroll replies only he and the kid who cuts the lawn — Ryan Ross, John and Lori's son.

Mare immediately runs back into Mr. Carroll's house to view security footage of his backyard from the night of Erin's murder, and the footage shows 13-year-old Ryan rolling up on his bike to break into the shed and take the gun. 

Mare shows up to Ryan's school, where he sees her while outside at recess and runs away. He runs straight home and tells his mom that Mare knows what happened and that she's coming to get him. It's at this point that we know Lori clearly knew all of this and hid it from Mare. In an emotional scene, Mare shows up to their home and takes Ryan into custody.

Ryan found out about the relationship between his dad and Erin through reading texts on his dad's phone. Ryan said he confronted his dad about it, but promised to keep the affair secret if his dad ended the relationship in order to keep the family together.

Thinking the relationship was over, Ryan was at Frank's house on the night of Erin's murder when he saw his dad outside on the phone. Ryan later grabbed the phone out of his dad's jacket pocket, only to see that Erin had called and texted John. 

When Ryan got home, he rode his bike to Mr. Carroll's house to get the gun, which he admitted to knowing about from mowing their lawn and seeing it in the shed. He then rode his bike to Brandywine Park and waited for Erin in the park as she was dropped off by Deacon Mark.

Ryan pulled the gun out on Erin, but she tried to grab the gun away from him. He then fired two bullets and killed her. 

Ryan said he only wanted to scare her away from his family and had no intention of killing her. He later brought the gun back to the shed rather than try to hide it or throw it away.

Scared and unsure what to do, Ryan said he called his dad and told him what happened. It was John and Billy who took care of putting Erin's body in the creek. 

Ryan, John and Billy were intent on keeping the murder a secret in order to protect the family. Ryan even lied to his mom about his dad having an affair with another woman in order to protect them from being caught for murder.

Lori said that she found out about her son's involvement from John, who came over to the house and told her before going out to fish with Billy. Lori promised to keep it a secret to protect her son and said she never would've come forward had the police not figured it out.

After being questioned by Mare and the police, Ryan is taken into a juvenile facility in a stunning turn of events that almost no one saw coming.

Did John kill Billy during their last fishing trip?

No, John didn't kill Billy while out fishing, but that was certainly his intention in order to make it seem like Billy took his life instead of turning himself in. Ultimately, John wanted Billy to take the fall for the murder and the affair on behalf of the family.

At the beginning of the episode, we're at the river where we last left John and Billy fishing together and Mare in pursuit of Billy, whom she believes was Erin's murderer.

John pulls out the gun from the tackle box to shoot and kill Billy to make it seem like Billy killed himself. But as Billy tells John to pull the trigger, he can't seem to do it.

Mare appears from across the river and tells John to put the gun down. John then tries to shoot himself in the head, but Billy tackles him into the river to prevent him from doing so. The two brothers then fight as each tries to get control of the gun, with Billy mostly trying to keep the gun out of John's reach.

Mare then sprints across the river and tackles John, knocking the gun out of his reach and apprehending him.

If Dylan didn't kill Erin, why did he burn her journals?

So Dylan Hinchey, despite being the prime suspect for much of the investigation into Erin's murder, was completely innocent. 

We find out from Erin's best friend, Jess Riley, that it was her idea to burn the journals to keep the police from finding out certain information, such as who DJ's real father was, so that Dylan's parents could keep custody of DJ. Jess said burning the journals was what she thought Erin would've wanted.

We don't see Dylan until about a half hour into the finale when he appears at Lori's doorstep. He asks if Lori knew that her husband was the father of Erin's child, which she denied having any knowledge.

Despite not being the father of the child, Dylan brings Lori money that she can use to take care of DJ's medical needs.

What did Jess Riley find in Erin's journal?

We find out within the first few moments of the series finale that John had an affair with Erin and was the father of DJ.

The photograph that Jess recovered from Erin's journal and gave to police showed Erin and John together. Jess told police that she found the photo when they were burning the journals and that she kept it a secret from Dylan that John was actually DJ's father.

John said his affair with Erin began at the Ross family reunion trip in 2017, and he confirmed that he was the father of DJ. While Erin was dating Dylan, John sought for her to get an abortion, but she refused.

John said that he and Erin used prepaid phones to talk and communicate so that no one could find out about their affair or track their conversations.

Outside of the courtroom following his arraignment, John pleads with Lori to take DJ into her home and raise him. We see later that Lori does take him into her family and brings DJ to get his ear surgery done.

Who got custody of Drew?

In another stunning and heartbreaking turn of events, we find out that Carrie is dropping her attempt to take custody of her son Drew after admitting to Mare that she had started taking drugs again for several months. As Carrie heads back into drug rehabilitation, Drew stays with Mare, Helen, Frank and Siobhan Sheehan.

Did Siobhan leave Easttown and go to Berkeley?

Siobhan ends up going across the country to Berkeley after she and Mare have a conversation about it at home. Mare brings up Berkeley after hearing about it from Frank, but Siobhan says she doesn't want to go because her whole life and family are in Easttown. 

But after asking for her mom's advice, Mare tells Siobhan to go to Berkeley. 

What is the future for Mare and Richard's relationship?

Richard Ryan appears as Mare's date at Frank and Faye Sheehan's wedding. But Richard leaves Easttown for a job as a professor at Bates College for a year. Before leaving, Richard tells Mare that he'll come back to Easttown and that their relationship will be just fine.

As "Mare of Easttown" concludes, we see that Mare — played by Kate Winslet — is in a much better spot than when we met her at the start of the series.

Mare's family life is better, and as a result, she's happier. She's dating Richard, albeit long-distance, and spending quality time with her mom Helen, her daughter Siobhan, her grandson Drew, her ex-husband Frank and his fiancé Faye.

Mare is also able to heal the wounds that were caused between she and Lori in the wake of the murder investigation. 

After John was arraigned, Lori and Mare look at each other but don't talk, as Mare is clearly upset with her best friend for impeding the investigation.

It appeared that their relationship was all but ruined, as Lori told Mare that she never wanted to see her again and blamed Mare for taking away her whole family. It looked like Mare doing her job meant losing her best friend.

Later, Mare goes to Lori's house as a peace offering to make things right with her best friend. They make up and hug in an emotional scene, repairing the damages that were briefly there between the two.

The series finale closes out with Mare finally beginning her healing and grieving process by confronting the demons that have been haunting her for much of her life. The episode ends with Mare opening the attic door and climbing up to the attic, the place where she found her son Kevin dead after he hung himself.