“Walking Dead” fans have been replaying episode 3 over and over since last week. Glenn’s (Steven Yeun) fate was left unresolved while Rick (Andrew Lincoln) found himself in a dangerous situation surrounded by the horde. But episode 4, titled “Here’s Not Here,” didn’t touch on any of that. Instead, AMC viewers learned about Morgan’s (Lennie James) backstory and how he changed his ways from his days “clearing.”

Episode 4 of Season 6 picks up at Alexandria. It turns out that Morgan didn’t kill the final member of the Wolves. He brought the man back to the holding cell where Rick held him when he first arrived at the safe zone. With the threat now locked up, Morgan recounts the exchange they had when they first met in the woods. The Wolves said they wanted “every last bit” of him, and Morgan plans on giving him that. The episode then cuts to the past.

The flashback begins at Morgan’s old apartment, which had messages written all over it. He’s freaking out and talking to himself when he knocks over a lantern. The building goes up in flames -- but Morgan survives. With his home now gone, Morgan heads into the woods. However, he’s still taking his job of “clearing” seriously. He piles all the bodies of walkers up and sets them on fire. This area is now his home. He creates spears to guard his surroundings and protect himself from other walkers. Like the apartment, this new zone is riddled with phrases and messages -- “clear” and “here’s not here.”

But Morgan has a dark side. He’s not just killing walkers. He’s killing innocent humans too. When he stumbles into two people running through the woods, Morgan impales one in the neck with his spear and strangles the other with his bare hands.

“You don’t,” he yells at himself while strangling the man. “You know you don’t.”

It’s almost as if he’s trying to convince himself he doesn’t like killing. But it’s very clear that this incident was not an accident or his first kill.

The sound of a goat draws Morgan to a cabin in the woods. He makes an attempt to steal the goat, however a man calls out to stop him. “I’m still figuring out how to make cheese,” he explains. But that’s not a reasonable excuse for Morgan. He breaks out his gun, firing at the man.

Despite the gunfire, the man still offers Morgan some falafel if he puts down his weapon. However, Morgan is a lost man, a shell of the person “Walking Dead” fans met in Season 1. Nothing the man says is registering. Instead, he continues to wield the gun while trying to break into the cabin. The mysterious man warns him one last time to drop the gun, and when Morgan fails to listen, he knocks Morgan out with a bo staff.

Morgan awakens to find himself locked in a cell inside the cabin. But this isn’t a prison. The man provides him with a plate of food.

“Kill me,” Morgan says when the man asks his name. He yells it over and over again, but his host is not interested in ending his life. The man introduces himself as Eastman (John Carroll Lynch) and tosses Morgan a book -- “The Art of Peace.”

For a couple days Morgan and Eastman sit in silence around the house. Eastman tends to Tabitha, his goat, attempts to make cheese and practices with his bo staff. Eventually he breaks the silence, telling Morgan a little bit about himself.

Eastman was a forensic scientist from Atlanta prior to the outbreak. He worked for the state determining if bad people released from prison would continue to be bad people.

When he asks Morgan what his job is, Morgan replies, “I clear.” Morgan explains he kills anything that gets near him. Eastman asks why, to which Morgan says it’s why he’s still here.

Despite Eastman’s generosity, Morgan is trying to break out of his cell. But Eastman is not giving up on his captive. He tries telling Morgan he’s suffering from PTSD after losing his family. However, Morgan insists that he kills because that’s what he does.

“I’m going to kill you,” Morgan says to him. When Eastman questions him, Morgan says that he has to “clear.”

Although Morgan just threatened him, Eastman promises him that everyone can heal. He tells him the door to the cage is open -- and has been open all along -- and that Morgan can either stay on the couch or go.

“I will not allow you to kill me,” Eastman warns Morgan before he opens the door. “I will not allow that.”

Morgan doesn’t listen though and charges at Eastman. He slams Eastman into a wall, breaking a piece of sheetrock with a child’s drawing on it. Morgan tries to strangle Eastman, but his captor ultimately gets the upper hand. When Eastman sees the drawing broken, it looks as if he’s going to kill Morgan. But when Morgan utters the words “kill me,” Eastman snaps back to reality. He once again reiterates Morgan’s two choices -- the door or the couch. Morgan chooses the cell, closing the door behind him. However, Eastman opens it before exiting the room.

Once the two calm down, Eastman explains he used Aikido to subdue Morgan. Working for the state was a stressful job that began to eat away at him. One day his 5-year-old daughter gave him a rabbit’s foot she won at a carnival. She told her dad it would bring him luck, and the next day he found a flyer for Aikido.

Eastman continues to open up, but Morgan remains silent. One day he asks Morgan to accompany him on a trip to scavenge for supplies; however, Morgan refuses to move from his cell. Eastman decides to go on his own, but he asks Morgan to watch over Tabitha while he’s gone. Morgan stays silent and opens “The Art of Peace.” The first page says, “Avoid killing even the most evil person.”

Shortly after, Morgan hears cans rattle, signaling something moving on the property. Although Morgan doesn’t move at first, the cries of Tabitha draw him outside to protect the goat from walkers. Despite freezing at first, Morgan focused on Tabitha, using that energy to help him kill the walkers and protect her. It’s the first sign of change in him.

After killing the walkers, he brings Tabitha inside and drags the bodies to the area to which he watched Eastman drag others. It turns out Eastman buries every single walker he kills. And that’s not all. He also uses their IDs to create grave markers.

Eastman finds Morgan at the gravesite and thanks him for protecting Tabitha. He then brings him back to the cabin where he tells him he has to fix the fence he broke. However, he also has a gift for Morgan. Eastman chopped off the tip of Morgan’s spear and made him his very own bo staff.

The two begin to train together, with Eastman wearing a “Terrapin” T-shirt, a nod to the real-life Terrapin Brewing Co. that recently created a “Walking Dead” blood orange IPA. He teaches Morgan to move forward and embrace the code to “never do it again.” It’s as if Morgan is a brand new man.

Walking Dead Season 6, episode 4 Despite losing his family, Morgan (Lennie James) is able to change thanks to Eastman (John Caroll Lynch, not pictured) in Season 6, episode 4 of "The Walking Dead." Photo: AMC

But like Morgan, Eastman has his own dark past. One day when Morgan asks Eastman about the cell, his friend confesses he had it installed a couple of years after he and his wife built the cabin.

Eastman reveals his wife, daughter and son didn’t die after the outbreak. They were killed by a psychopath named Crighton Dallas Wilson with whom Eastman had worked as a forensic scientist. Crighton had totally beaten the system and had everyone convinced he was a changed man. However, Eastman explained to Morgan he knew Crighton was lying.

One day Crighton figured out Eastman wouldn’t sign off on his release from jail and attacked him. Crighton could have killed Eastman, but Eastman was able to fight him off thanks to his training in Aikido. Unfortunately, Crighton knew the right people and ended up breaking out of jail. He went straight to Eastman’s house and murdered his family before walking down the street to the police station and turning himself in. His sole reason for breaking out was to destroy Eastman’s life.

That’s why Eastman installed the cell in the cabin. A year after the incident, Eastman hatched a plan to get Crighton, bring him to the cabin, and watch him starve to death.

But did he end up doing it? Morgan asks him that question, but Eastman doesn’t answer. Instead he says, “I’ve come to believe that all life is precious.”

Although light on the small talk, the two continue to grow closer. When Eastman says they need to go on a run to get a crowbar and tarp, Morgan tells him he knows exactly where to find that. He brings Eastman into the woods to the area he had camped at. His bag -- which contains the supplies -- is still there.

Eastman is able to get a look at the old Morgan again, seeing the burned corpses and odd messages written on the rocks. He questions Morgan about his family, and Morgan finally opens up about his wife, Jenny, and son, Duane. However, the talk triggers the darkness in him. Eastman demands Morgan do his “forms” as a way to redirect that energy. Morgan doesn’t want to do it there, but Eastman insists. He begins his forms when a walker surfaces from the woods.

Eastman tells Morgan to get the walker, but Morgan freezes when he sees the walker is the man he strangled to death. The walker is about to attack Morgan when Eastman runs up and pushes him out of the way. He gets bit on the back in the process.

The attack triggers something in Morgan, causing him to begin yelling and rambling like his old self. He tries to attack Eastman, begging his friend to kill him. But Eastman refuses. Instead, he packs the body of the walker onto his cart and returns home.

Morgan stays behind, back to his old ways of “clearing.” However, when he finds two people in the woods he doesn’t kill them. Watching them triggers something in him, leading him to grab his bo staff and return to the cabin.

Unfortunately when he gets back he finds a walker eating Tabitha. He kills the walker and wheels the body and Tabitha to Eastman at the grave site. It’s there that Morgan discovers a grave marker with Crighton’s name on it.

Weak from the walker bite, Eastman confesses he abducted Crighton while working on plots along the side of the road. He knew no one would know to look at the cabin, and locked Crighton up to let him starve to death. It took 47 days until Crighton finally died. At that point, Eastman said he was gone, just like Morgan was when he first found him.

“It didn’t give me any peace,” he tells Morgan. “I found that peace when I decided to never kill again.”

Eastman was going to turn himself in, which is when he discovered the world had ended. With no one to whom to confess his crime, he traveled the 31 miles to his house to cut his daughter’s drawing from the wall and bring it back to the cabin.

With his story over, he tells Morgan he’s welcome to stay at the cabin when he’s gone, but that he shouldn’t. “Everything is about people,” he says.

Eastman gifts Morgan with the rabbit’s foot before taking his own life. Morgan takes Eastman’s suggestion, packing his bag and bo staff before leaving the cabin behind.

Cut to the present, Morgan wraps up his story for the member of the Wolves. “And that’s it, every last bit,” he finishes.

His new prisoner asks if he thinks things could work out that way for him. But the truth is he’s not interested in changing. He shows Morgan a nasty looking wound on his side and says he broke into Alexandria to find medicine to save himself. However, he adds if he doesn’t die, he’s going to kill Morgan and everyone else in Alexandria -- including the children.

“Those are the rules,” he explains to Morgan. “That’s my code.”

Even with that confession, Morgan doesn’t kill him. Instead he leaves him tied up in the Alexandria cell and locks the door. Episode 4 of “The Walking Dead” ends with Morgan running as someone yells to open the gates.