Without further ado.

A. Mr. Park

He has a doppelganger who’s still alive. If Sigma arrived in 2001, and Mr Park was one in that group of first time-travelers, then Mr. Park arrived around 2001, too. That means he’s been avoiding his doppelganger for 20 years.

1. I like that SeoHae took him to task for not taking charge of his own life.

SH: Why are you blaming me? You’re in charge of your own life.
TSul: (not wanting a confrontation between the two) Stop this.
SH: You said it’s all predestined. Getting taken to the Control Bureau and not seeing your family must be your destiny. So why are you taking it out on me?

Meaning, he couldn’t blame her for the bad things that happened to him if he believed everything was fated to happened. He should blame fate.

To me, he just wanted to vent his frustration on somebody. He was like a Sisyphus, too, because he was trapped in this endless loop.

Park: I’m angry because I can’t do anything about it. I’m furious because it’s all fixed.
SH: Do you feel better when you say that? Do you say that it’s impossible to change in things in case you fail to do it? You’re just making an excuse.

Seohae thought he was being fatalistic. She scolded him for his defeatist attitude, then enlightened him about a discovery she made.

SH: Some things have already changed. I was supposed to get shot. It was written in my diary that I’d be crippled after getting shot.

Then she showed her vial of medicine which she had brought from the future for contingency measures. She had no need for it so she gave it to one of the minions to administer to his crippled brother.

Three things:

So, she did bring home medicine in those jars! She came prepared. But unlike Sisyphus, she didn’t bring medicine for blackmail.

There were more notes in the diary that we aren’t privy to. Thank goodness! I was wondering why she would brought around that diary if she only had two or three pages of scribbled notes. She could have torn off those pages and carried less baggage.

Her words had an effect on Mr. Park. He visited his doppelganger’s house and stoned him for hitting on his wife. I’m hoping that her encounter with Hyunki had the same effect on him, too, and that he would awaken from the Control Bureau’s manipulation of his perception of reality.

2. Sigma made a subtle dig about Mr. Park’s family NOT wanting to take the uploader, and be reunited with him. To his wife and daughter, they were better off without him because his doppelganger was a wife-beater.

Park: Why didn’t you send my wife and kid?
Sigma: I kept my promise. I found your wife and daughter and took them to the uploader myself. It was their choice to whether to get on it. Maybe…she doesn’t want to see her daddy.
Park: (fake laughter) I swear, I’ll kill you with my own hands.
Sigma: (chuckling, too, and playing with the monkey) Some people can’t handle it when they’re treated with respect.

My guess is Sigma was being tactful or DIPLOMATIC when he told Mr. Park that her daughter didn’t want to see her daddy. Most likely, the daughter vehemently rejected going back to see Mr. Park again. Sigma felt offended that he was being considerate of Mr. Park’s feelings when he didn’t inform Mr. Park of the whole truth, but Mr. Park threatened to kill him with his bare hands.

Also note Sigma’s condescension for Mr. Park. He continually made snide remarks about Mr. Park to Taesul as if he was trying to align himself with the genius instead of a dirtbag like Mr. Park. I’m sure, however, that Taesul would much rather trust Mr. Park than Sigma.

3. I agree with @Janey when she said that it didn’t make sense that Mr Park was sending money to his doppelganger’s wife when he knew that the money would cause his doppelganger’s rage and physical abuse. Probably Mr. Park was concerned that the wife and daughter had no money for living expenses and expected the wife to stash it? Probably he wanted to atone?

4. The alliance between Sigma and Mr. Park is interesting because ordinarily, Sigma should detest Mr. Park because in his past life, he was like his abusive dad. Perhaps Mr. Park didn’t know about Sigma killing his abusive dad.

B. Kim Alice and Seojin

Like Mr. Park, Alice Kim has a doppelganger who’s still alive, and it’s SeoJin. Since Alice Kim was part of the first wave of time-travelers, she must have arrived sometime around 2001, too. That means she’s been avoiding her doppelganger SeoJin for 20 years, by hiding in the orphanage among the young illegal aliens.

1. Like Sigma’s comment about Mr. Park had an undertone of condescension, Taesul’s remark to Alice Kim was intended to be insulting. Although he knew who she was before she showed herself, he feigned ignorance so he could call her “evil.” From Ep 10:

Alice: But what are you doing here?
Tsul: Well… some evil person made a scary drug, and there’s someone who’s suffering because of it. I came to ask if there’s any way to cure her. Kim..uh…Agnes.

He was pretending not to recognize her. And he called her “evil.”

Alice: How did you find me here? Was it Park Hyungdo? Is he the one who told you?
Tsul: Was his name Hyungdo? I see…well…
Alice: I don’t know what he told you, but what you’re looking for isn’t here. This is just a plain orphanage.
Tsul: All right. Stop fooling around. I don’t have much time. Kim SeoJin. Those papers. You wrote them. I read them once when I couldn’t sleep. (observed her. This was the older Seojin) You were one of them. So you were on the advance team. What a surprise. Give me the cure.
Alice: There’s no such thing.
Tsul: You made the poison. The one used to torture people at the Control Bureau. You must have its cure. Alright. Let me tell you something. The last time I met you (he meant the OTHER Seojin) at Jaae Hospital when I ran into you while running away from there. So I have a bit of a grudge against you right now. Actually, a huge grudge.

He was reminding her of their last encounter in case she’d forgotten since she was a time-traveler from the future.

2. Alice Kim had no problem working with these young time-travelers, but Seojin wouldn’t have worked to help them because she hated them.

Sigma: Why are you here?
Tsul: To get the cure.
Sigma: Oh no! I guess that girl got the injection. You probably know this already but Agnes made that drug to torture people from the future.
Tsul: (looked at Agnes, Agnes was looking down as if she was ashamed about this)
Sigma: You see, she despises illegal entrants. So why should we give you the cure? Agnes, I guess he thought we’d just hand it over. (laughing) On a side note, I really don’t understand why one would make poison and also create an antidote for it. You shouldn’t do something you’d regret in the first place. Why go to such lengths to undo it? Right, don’t you agree? (asking the room) In my opinion, people are fickle-minded because they aren’t honest with themselves.

In the past, Seojin hated the time-travelers and she aided the Control Bureau in rounding them up and torturing them. She created the drug most likely to induce them to talk and to eliminate them. But when she survived the nuclear holocaust and became a time-traveler herself, it seemed like she had a change of heart. She returned as Alice Kim and created the antidote to undo the damage that she did.

I’m hoping that remorse and a desire to make amends are the reasons she was working with the orphan and finding them new homes abroad.

3. I found it fitting that ALICE showed Taesul how to use the antidote on Seohae since her doppelganger SEOJIN was the one who made the drug for the Control Bureau to use on Seohae. I see this as her atonement.

But let’s see if she sufficiently regretted her past that she would be willing to be an agent of change in the future.

4. Alice Kim’s speech

Taesul opened the vaccine case and noticed a needle missing.

Tsul: Where’s number one?
Alice: (couldn’t meet his eyes) That one failed.
Tsul: (he was being sardonic, of course) My gosh. What a relief.

I think that missing injection was the one that his Hyung had with him and injected into Taesul.

Alice: You know, right? This is exactly what Sigma wants.

Yes. Just like Sigma had planned for set it up that Hyunki would go raid the closet for weapons, Sigma intended for Taesul to go rescue Seohae in that weird space-time continuum.

Alice: I deceived you my whole life. I made you look like a lunatic and put you in danger. This morning, I even locked you up. Will you still get this shot? (she wanted him to back out of this plan because she thought he might not come out again)
Tsul: I have no other choice.
Alice: Even if you do this, the future won’t change, Taesul. It’s not about saving that girl. Don’t you get it? For you, it’s the future. But for me, it’s the past. No matter how hard we try, we can’t change our past. We can’t undo our mistakes or the things that we regret. The future won’t change either. Because your future is a mirror image of your past. It’s your reflection in the mirror. Even if you can’t stand what you see in the mirror, and feel ashamed of it, you can’t change it. Because that’s who you are. Taesul. You can’t beat the mirror no matter how fast you are.
Tsul: Seojin, I don’t think I agree with you. The mirror can’t be faster than us.

Hmmm… I don’t know Taesul would explain this. But to me, technically, the mirror can’t be faster than us. And that’s because the light has to bounce off from us, travel to the mirror, and then reflect back to us. But light travels so fast, that it seems as if our body and our reflection are moving simultaneously, when actually there’s a delay.
Of course, there’s additional delay too when our brain has to decode what it’s seeing.

Alice’s speech shows us the difference in mindset between her and Seohae. She’s fatalistic, too, like Mr. Park, while SeoHae is brimming with positivity and hope. She can do it.

C. Seohae

Like Seojin and Mr. Park, Seohae’s version is already alive in 2020. Her birthday was on Sep 30, 2012, so she was only 8 at that time. She’s avoided meeting them, but her mother later learned that she met her at the amusement park, and she and her father had a long conversation together.

1. I like that she accompanied Taesul face his past. If it had been Alice/Seojin with Taesul, she would only have droned on and on about the immutability of time and his self. In contrast, Seohae held his hand and led him on. She told him to keep moving forward because moving forward was the only option. Moreover, she was able to give him hope when he felt ashamed of his past arrogant self and fell into despair.

I do NOT think that scene with the wasteland is something that will happen in the future. I think it’s more like that dream sequence he experienced in Episode 6 after Seojin gave him some pills (which probably was the low dose or experimental stage of this poison she created).

He was wandering through different timelines – or different memories — in his mind and the wasteland was the projection of his selfish, shameful, and barren existence. He was “awakened” to his empty life and it looked like this no-man’s-land. But despite its desolation, he preferred to stay there than face his shame, guilt, and regret.

Tsul: I don’t want to see it anymore. Do you know what we’ll see once we walk through that door? My brother’s funeral. (pointing to the door) And me turning into a rich bastard who hurts everyone around him. I’ve never been happy in my life. Not even a single day. You can go alone.
SH: How can you not have happy memories?

I like how she dished out her SOB STORY. Compared to her real wasteland, his was endurable. That put everything into perspective for him.

SH: I lived on rotten canned foods in a bunker after the war, but I have happy memories. After the war, my dad took me to school every March. The school was in ruins, but I packed lunch and my backpack to go there. It was the one day I could put my worries to rest and just play with my dad in the empty classroom. And I had so much fun.

She shared more of her happy memories. This segment reminded me of Julie Andrews in the “Sound of Music” singing about her favorite things so she wouldn’t feel so bad.

SH: We all have trivial but happy memories. That’s what keeps us going. I’m sure you have some too. So try to recall them.

Because Seohae guided him to face his inner turmoil, he was able to avoid the dreaded funeral. That’s why they found themselves at the shore of the West Sea — which I’m sure we all remember — is the meaning of Seohae’s name.

2. Seohae was proving Seojin wrong. Seojin believed they couldn’t beat the past no matter what they did because the past eventually caught up with the future. For the past few episodes, it appeared as if Seojin’s assertion was correct when viewers are shown fragments of Seohae’s past. Seeing the back history created an impression on the viewers that:

a. Seohae’s past was catching up to her,
b. her “future” (or her present time) was finally making sense.

On the surface, it would appear that Seohae was merely following a cycle, or a time-loop. But when her choices are studied, it becomes evident that all her decisions are new, and each decision opens up a new pathway for her. She isn’t repeating her past life, like Seojin said. That’s why she survived Hyunki’s assassination attempt, and she didn’t die on her birthday.

She was continually throwing a monkey wrench in the works so Sigma’s schemes were constantly being thwarted.

D. Sigma

Sigma’s unique among the first wave of time-travelers because he’s the only one without a family and a former self to go back home, too. As of Episode 12, neither his doppelganger nor his younger self has shown up.

1. His age

Although he looked much older than Taesul, he was actually Taesul’s peer. Taesul was born in 1982 so Sigma must be 38 years old, too, in 2020.

2. Sigma is anti-family.

I’m sure you all noticed this by now, right? He mocked people’s attachment to their families.

He wondered what all the fuss was about when SeoJin’s cried at her father’s funeral when millions of people were going to die in a nuclear war.

He didn’t share his fund manager’s excitement at having a baby boy.

He didn’t believe Hyunki could feel remorse for neglecting his mom. I wonder if he knew that Hyunki time-travelled to the past with just ramen in his luggage. I’m holding out hope that Hyunki will be a wild card

He belittled Mr. Park’s desire to be reunited with his wife and daughter.

He was determined to keep the two brothers Taesan and Taesul, even writing on the wall, “Don’t look for your brother. If you do, you’ll die.”

3. Hero-worship

Methinks he’s jealous of Taesan’s and Taesul’s brotherly bond. He hero-worshipped Taesul when they were kids, and wanted to be Taesul to approve of him when he killed his father and granny in the bomb blast. I wouldn’t be shocked if he planned to replace his dead family with Taesul.

But when Taesul pushed him away, he wanted to kill him, too.

This hero-worship of his is still evident during the long scene in Episode 11. For one, he spoke to Taesul in a deferential way. For another, he was trying to impress Taesul with his cunning arguments which Taesul dismissed as sophistry or specious reasoning. Just like when they were kids when he’d been eager to win Taesul over to his side, he wanted Taesul on his side again.

It should also be noted that as adults, he and Taesul are asocial and loners. They were difficult to work with. But while Taesul had his hyung protecting him, Sigma had been all alone.

4. Jealous of Seohae, too?

It’s interesting that he’s never mentioned Seohae by name and only calls her “the girl.”

He’s been targeting SeoHae all along.

5. Sigma’s Sophistry

Sigma: Why shouldn’t the world end?
TSul: Well, where do I begin. First off, normal people wouldn’t want to world to end.
Sigma: You’re wrong. Go ask anyone you see on the streets. “In front of you, there’s a nuke button to end the world. Will you press it?” I bet so many people will say yes. Look on the internet. You see countless people who want the world to end. And some people say this, “There are too many people on this planet. We must wipe out 75 percent of the world population.” Han Taesul, I bet you’re no different. Why don’t we do a little experiment? (gives him a gun) Take it. You know how to shoot a gun, right? Just pull the trigger. (Taesul grips the gun) Shoot me. If you kill me now, you can save the world. Shoot me. Come on.
Park: Do it.
Sigma: Shoot me.
Tsul: (relaxes his grip)
Sigma: You just pressed the nuclear button. I bet this was your train of thought. If you kill me, my buddies here will kill you. They’ll also kill Agnes and 101. You won’t be able to get the cure. So that girl will also die. You made a choice that will end the world just because of a girl. But don’t beat yourself up. That’s just how people are. Even if everybody were to die, they’d still put themselves, their families, and money first. Agnes is no exception. She can’t shoot me because I’m taking good care of her mother. Neither can 101 because he wants something from me. (plays with the monkey) I gave everyone a chance, but not a single person chose to save the world.
Tsul: (just winces at him)

There are three ways to look at Sigma’s argument here:

First, if we follow Sigma’s logic, it will seem as if he’s offering Taesul a choice of whether to kill him or not. In reality, he only gave Taesul an ILLUSION of choice. He knew that he left Taesul with NO Choice because if Taesul pulled the trigger, then his henchmen will kill Taesul, Agnes, 101, and Seohae.

Taesul had no choice but to restrain himself from killing Sigma. This kind of fake choice is called “Hobson’s choice.”

Second, as much as we want an evil person dead, there’s something ingrained in our moral fiber that deters us from killing an unarmed individual. Sigma attributed this reluctance of Agnes, Mr. Park, and Taesul to kill him as selfishness and self-interest. But he didn’t consider that they could have hesitated to kill him because they saw him as pitiful human being.

Third, when I listened to Sigma’s long monologue, there seems to be latent envy that everybody else had someone they would choose to save. Except for him. Agnes was going to save her mom. Mr. Park was going to save his family, and the minions. Taesul was willing to save Seohae at all cost. Same with his hyung who’d die to save him. Then Seohae traveled from so far to save Taesul.

But there was no one for him.

In a sense, he was just like Taesul who told Seohae that no one was waiting for him.

Tsul: I’ve been wracking my smart brain, and you should be the one who goes back. They need you more than me to save the world. No one’s waiting for me to come back anyway. You know that everyone hates me.

Taesul sounded pathetic when he said that but he meant that. Hence, when he regained consciousness, the first thing he asked her was “Did you just say you missed me?” Similarly, Sigma looked pathetic when he asked Taesul if he remembered him. He sounded a bit desperate, a bit hopeful to be recognized by Taesul as his long-lost classmate. Unfortunately for him, Taesul didn’t remember him.

To me, this highlighted the difference between the two men. Taesul had always been shown love whether he realized it or not. People like Eddie Kim were eager to serve and care for him. But no one had extended the same devotion or loyalty to Sigma, not even his broker whom he enriched.

This is it for now.