Spoiler alert! This article contains multiple spoilers not only about the character of Jack Kline, but the entirety of Season 13. Read on at your own risk!

Season 12 ended with a bang as Jack Kline, nephilim son of Lucifer, was born. Fans were shocked to see a young adult huddled in the corner, eyes glowing yellow as the season ends. We were left to wonder whether he would be just as evil as his father.

As season 13 kicked off fans are greeted by a defensive Jack attacking Sam and Dean, then disappearing. We spent exactly half an episode wondering if he would be evil. Many, if not all, fans were won over the moment Jack smiled and joyfully exclaimed, “I like nougat” to a wary sheriff.

Jack’s character faces many trying situations throughout the season resulting in impressive character development. Actor Alexander Calvert expertly navigates the waters of the Supernatural world as he perfectly portrays Jack’s naiveté and innocence while also highlighting his fierce determination to help and protect others.

Let’s take a look at Jack’s five biggest moments in Season 13.

1. “The Rising Son” – Episode 2

Following an intense battle with angels determined to capture Jack, the Winchesters discover that angel blades cannot kill him. Dean and Sam are both visibly confused and alarmed as Jack extracts the angel blade from his chest clearly unharmed.

Back at the bunker Dean hears an odd noise and discovers Jack in his room repeatedly stabbing himself with a knife, his wounds healing instantaneously. Dean charges into the room grabbing the knife away from Jack.

DEAN: Okay. What the hell? Give me that. You—Don’t be an idiot. Look, A, this is not gonna do anything to you, okay? And B, you… What the hell?

JACK: Exactly. What the hell am I? I can’t control… whatever this is. I will hurt someone.

DEAN: You know, my brother thinks you can be saved.

JACK: You don’t believe that.

DEAN: No, I don’t.

JACK: So… if you’re right?

DEAN: If I’m right… and it comes to killing you… I’ll be the one to do it.

Why is this significant?

We see Jack begin to grabble with the reality of his existence and what being a nephilim means. Thus far he’s had limited exposure to other beings, and sees only fear in Sam and Dean’s eyes when they look at him. This is the first time Jack openly admits his inability to control his power and confesses to Dean he worries about hurting someone. Dean promises to kill Jack if necessary, which only serves to make Jack even more wary.

We see the result of this conversation later as Jack begins to mimic the brothers, fearing his powers and believing he must be evil. Will he inevitably go bad as Dean says? Is he capable of learning control and being good? Not even Jack is sure of the answer and he is now fully aware of how dangerous he is.

2. “Patience” – Episode 3

Back from a solo hunt, Dean arrives at the bunker and casually asks Sam if Jack has gone evil yet. Frustrated, Sam argues that Jack is not and will not go bad if they teach him to control his powers. He argues that Jack is not evil just because Lucifer is his father. Just as Dean saved Sam from drinking demon blood, he asks Dean to help save Jack.

However, Dean is not interested in Sam’s attempts to redeem Jack. In the heat of the argument Dean admits to seeing only loss and death when he looks at him.

DEAN: Look, I know you think that you can use him as some sort of an inter dimensional can-opener and that’s fine, but don’t act like you care about him! Because you only care about what he can do for you! So if you want to pretend, that’s fine! But me? I can hardly look at the kid! Because when I do all I see is everybody we’ve lost!

SAM: Mom chose to take that shot at Lucifer. That is not on Jack!

DEAN: And what about Cas?

SAM: What about Cas?

DEAN: He manipulated him, he made him promises, said, ‘paradise on earth’ and Cas bought it and you know what that got him? It got him dead! Now you might be able to forget about that, but I can’t!

Unbeknownst to the brothers Jack is listening to their fight from the hallway. We know that Jack longs for acceptance and wants to please both Sam and Dean. It is at this moment he realizes Dean holds him responsible for Mary and Castiel’s death. Distressed by the argument Jack accidentally uses his powers to awaken Castiel in The Empty.

Why is this significant?

The limits of Jack’s powers are unknown at this point. Jack has already established that he cannot control his powers, and yet he is able to reach through the abyss and awaken Cas with pure desperation and longing for his chosen father figure. We see both how powerful Jack is and how badly he wants to help others.

In waking Castiel, who is then able to annoy his way out of The Empty, Jack has also played a hand in waking up Dean. Thus far Dean has barely been able to look beyond his own grief over Mary and Cas. However, Jack is directly responsible for the “win” that Dean so desperately desired. Thanks to Jack, Team Free Will 2.0 is formed and they are ready to fight their way to the apocalypse world and save Mary.

3. “Good Intentions” – Episode 14

Following their escape from Michael in the apocalypse world, Jack and Mary set out to locate Bobby and the rebel army. However, upon their arrival Mary admits to Bobby that Jack is a nephilim after Jack uses his powers to put on a shadow puppet show for the children. Bobby’s hatred for angels runs deep and he angrily demands that Jack leave their camp by daybreak.

Just before Mary and Jack depart angels attack the rebel army camp. Bobby immediately blames Jack for the incursion who insists he did not betray their location on purpose.

Mary tells Jack to hide, but he choses to stand and fight. In a demonstration of strength and loyalty, Jack kills Zachariah and his army of angels attacking the camp. Shocked by this show of force Bobby apologizes for judging Jack, but Jack has also come to a realization of his own.

BOBBY: Well, I don’t know what to say except thank you.

MARY: Jack, what you did was amazing.

JACK: I had to come back. Sam and Dean, they wouldn’t run. They’d stay and fight. These angels, what they’re doing, they’re not gonna stop. As long as Michael’s out there, this war will never be over.

BOBBY: So what are you saying?

JACK: I have to kill him.

Why is this significant?

Though he is not evil, Jack is once again exposed to the prejudice of humans against what he is when Bobby rejects him for being a nephilim. We see Jack constantly grappling with the fear of those around him as well as his own. However, the attack on the refugee camp allows Jack to show his true nature and his desire to protect others. From watching Sam and Dean he learns that the good guy will always fight for those in trouble.

Jack finally feels as if he is helping, rather than hurting, others by using his powers to defeat the angels. This major turning point drives his decision to stay with the rebel camp and strengthens his resolve to kill Michael.

4. “Unfinished Business” – Episode 20

Convinced that Michael’s decision to move his base camp farther away is a sign of their success, Jack decides to investigate the abandoned angel camp. Mary and several others accompany Jack on the recon mission wherein they discover the forgotten war map with Michael’s plans.

Mary is suspicious at once, suggesting that the plans are a trap. Jack, however, is adamant about attacking Michael immediately. Other members of Jack’s team find Kevin Tran whom they assume was a prisoner. As plans are discussed and preparations to leave the church made, Kevin reveals himself to be the trap Mary had predicted.

Jack and Mary try to talk Kevin out of it using the spell carved into his chest to kill them.

KEVIN: Michael says when I get to heaven, when he lets me into heaven, I’ll get to see my mom again.

MARY: I’ve been to heaven and what’s there, it’s just memories. Nothing’s real.

KEVIN: I don’t care! You don’t understand, I- you don’t know the things I’ve done. I just want this to be over.

JACK: Your spell won’t kill me.

KEVIN: Michael doesn’t want to kill you. He wants to break you. He said for me to tell you that even if you win, you still lose. I’m sorry.

Kevin then touches the sigil on his chest, activating the spell. The blast kills all but Jack and Mary whom Jack wraps in his wings to protect her.

Why is this significant?

This is the first time Jack is placed in a leadership role. It’s his decision to take a recon team and inspect the abandoned camp. It is also his first experience of losing soldiers in this war, a direct result of his decisions. He feels responsible for the deaths of his team and we see a distraught Jack surrounded by his companions as Mary lay unconscious. It is a blow to Jack’s confidence in his choices and he begins to question himself again.

The lighter side of this scene is Jack’s immediate reaction to protect Mary. As soon as Kevin raises his hand Jack grabs Mary and wraps his wings around her thus saving her life. We again see his instinctual desire to save people, a trait Sam, Dean and Cas would surely be proud of.

5. “Let the Good Times Roll” – Episode 23

After meeting Lucifer, Jack decides to give him a chance to explain his actions rather than blindly accept the opinions of others. He attempts to bond with his father while also giving Lucifer an opportunity to prove he is not evil. Lucifer tries to win Jack over through a series of half hearted good acts. Upon Jack’s request Lucifer even resurrects Maggie, an apocalypse world refugee for whom Jack felt responsible.

Away from Sam, Dean, and Castiel, Lucifer tries to convince Jack to leave Earth. He convinces him with the idea of exploring the universe together as father and son, exploiting Jack’s desire for family.

Jack agrees, but before they can depart Jack hears Sam’s distressed prayers and they return to the bunker to help. They find Sam and Dean at the mercy of Michael, and Jack quickly overpowers the archangel. Michael reveals his deal with Lucifer, and Lucifer steps in to stop Jack killing Michael.

Jack discovers that Lucifer has been manipulating him and intended to let Michael destroy Earth. Sam also reveals that Lucifer murdered Maggie. Lucifer deflects the charges but Jack uses his powers to force Lucifer to tell the truth.

JACK: Tell me the truth!

LUCIFER: She saw me when I was scouting out the bunker. She saw me and she screamed… so I crushed her skull with my bare hands. And it was warm and wet, and I liked it.

JACK: You’re not my father. You’re a monster.

When Jack rejects him, Lucifer admits he only wants Jack’s power. He slits Jack’s throat, steals his grace and disappears with Jack and Sam, who attempts to stop Lucifer at the last second.

Why is this significant?

Jack has struggled with his desire for family throughout this season. We see him mourn the death of his mother early on. He is again devastated when he discovers Castiel, the angel he chose as his father, is also dead. We see him bond with Sam, Dean, Castiel and Mary, but he is presented with a true blood relative when Lucifer finds him.

He wants to trust his father despite everything the others have told him. However, when Lucifer reveals his true nature Jack rejects him outright without a second thought. He chooses Castiel and the Winchesters when he realizes for himself that family doesn’t end in blood.

With Lucifer presumably dead, Jack will turn his attentions to saving Dean and destroying Michael once and for all. Will he succeed? We will have to tune in for season 14 to find out.

Season 14 premieres Wednesday, October 11 on the CW. Nerds and Beyond has even more 5 Biggest Moments posts coming soon to help you through the hiatus!