Yes. This was revealed in episode 15 when 2035-Seohae and her father arrived at the secret bar of 2035-Sigma. When they reached the underground facility, 2035-Sigma and the advance team were still there. Here’s a short timeline after 2035-Sigma allowed 2035-Seohae to use the Uploader.

• 2035-Sigma sent the missiles to 2020-South Korea
• 2035-Sigma was the first person to use the Uploader (explained in the earlier episodes) and went to 2001
• The advance team followed.
• The other “volunteers” or “refugees” Uploaded next.
• 2035-Seohae was called and went to 2020.

Short answer: because for all intents and purposes, they are a copy of the person in the past.

Long answer: They are not supposed to be in the past where their younger versions exist. Since their younger versions are in their proper time period, then they practically became a copy. However, it does not mean that they are literally a copy and there is an original left in 2035. Episode 15 established whenever they use the Uploader, the original from 2035 literally time traveled to the past.

Yes. We know there is only a single timestream because whenever the past version see their future version, the future version disappears. It means that they are exactly one and the same, from the exact same timestream. As explained in the previous question, the future version becomes a copy when they are in the past where they already exists. In addition to that, if they are from different timestreams then it should be fine to interact with each other because no one is a copy of the other, they will be both unique.

There is another proof of this which we will touch on in another question.

The Uploader was still developed. 2020-Taesul did leave the code to finish the Uploader in the laptop Eddie Kim gave him. However, Taesul no doubt time-locked it (will only unlock sometime in the future) and added other conditions–possibly it will only work with Seohae.

There is also the Uploader blueprints Taesul’s brother, Taesan, hid from everyone. When he woke up, he found out his brother killed himself to save the world. He did say that he will do everything to save and ensure Taesul lives.

Even if Taesul did not leave the code, Taesan still have a copy himself. However, I do believe Taesul did leave the code, we will come back to this later.

Don’t make Seohae mad at you … her aim is true!

No, time was not reset. If time was indeed reset then they would be back from the very beginning and everything will start all over again. Yes, that is the premise of the series title “Sisyphus”, however as was shown in the plane scene in episode 16, that is not the case at all.

The solution to this is the time bubble I mentioned at the beginning of this post. When Taesul killed himself, it delayed the development of the Uploader. Without it, everyone and every item from 2035 disappeared. However, the effects, interactions, memories, the diary Seohae wrote, information they shared, remained. This is proof that time was not reset.

What happened was the time bubble was popped when Taesul died. The result of popping the time bubble is the time periods that used to be inside it became fixed or set in stone. The time before the pop became fixed as the [new] past. The time after the pop was rewritten and became the [new] future. This is why the information written in the notebook 2020-Sigma was holding still exist. If time was reset that information should have been erased as well.

I think he’s reformed. Kang Donggi’s (Seohae’s father) wise intervention clearly made a mark in 2020-Sigma, it was shown all over his face! It was also the whole story behind why 2035-Sigma/2001-Sigma turned into a psychopath … no one cared for him, he was invisible, he was treated less than an animal. When Donggi showed his fatherly nature, which reflected in his eyes, face, and action, 2020-Sigma noticed it all and it changed him from the inside. It was proof for him that his assumption that no one cares about him is false.

This was later proven when he was shown freely doing artwork for strangers in a public park. He was no longer suicidal. His dark view of the world diminished or perhaps gone. He probably hates Taesul still but he’s dead anyway. It would explain why he tried to copy Taesul in front of his mirror … he has new plans, and there is the information from the notebook.

Which brings us to the next question.

I have no doubt it was Donggi’s notebook where he scribbled his thoughts to understand the connections of everyone … because he needs to stop his daughter from going back in time or meeting Han Taesul. Noticed how Donggi trained Seohae and tried everything to keep the knowledge of the uploader from her? He investigated and kept notes. Let’s go back to episode 15. Remember what 2035-Sigma said to Donggi in the Uploader room? Paraphrasing, “you know she made it to the past, safe and sound”.

Remember that scene in episode 16 when Donggi removed two items from his jacket before giving it to 2020-Sigma? He forgot something else … his notebook.

What did I say at the beginning of this post about creative writing? Show, don’t tell and if a scene won’t move the story forward, delete it. There was no need to focus on Donggi removing the items from the pockets of his jacket. There were even two scenes, one scene was in front of him and the other scene was a back shot. It was a clear sign that there is something the writers want to show us in those two scenes. It was not about the jacket. It was not about those two items he removed. It was about what he had forgotten … his notebook.

See? Even Sigma is laughing now.

It does not make sense, right? 2020-Taesul partially lied. What he actually meant was he calculated everything already and “saw” the outcome of his plans. Here’s the thing, the memories he got from the Dead-Taesul ashes was that version when they were getting married and 2001-Sigma shot Dead-Seohae. In the reality we watched, Seohae was not in a wedding dress, which Sigma also realized. If so, then 2020-Taesul never saw anything in advance.

What 2020-Taesul saw were the events of their previous attempt to stop Sigma. Based on that information, he calculated all the probabilities and set things in motion. He also admitted that he had to locked-up Seohae because it is very important that no one learns of his plans for it to succeed.

Taesul was also surprised that the gun men were still around when Sigma ordered to shoot them. This was another proof that Taesul was only relying on his calculations. There’s more, we’ll get back to this in a few.

Again, partial lie. Taesul also said this (paraphrasing): Find me. No matter what it takes. Find me. No matter when. Find me. Why?

He was reassuring Seohae that he planned for everything up to that point. That he knew “it is the only way” to save the world and to ensure they get another chance to be together. Yes, Taesul formed the plan to shoot himself after he touched the ashes of the Dead-Taesul.

This is the other reason why, as I mentioned earlier, that Taesul did leave the code for the Uploader in the laptop. If he did not, then there will never be a chance for Seohae to find him, it would be a futile sacrifice and it does not fit the character of Taesul.

He was so sure about everything. He was not afraid to shoot himself. Because he calculated, he knew, that eventually the Uploader will be developed and the next Seohae will travel back in time again.

Let’s not forget the new diary. Maybe Taesul left notes there as well and planned for the next Seohae to receive it. And of course his brother Taesan and the blueprints he hid.

He planned perfectly. He told Sun to park so he can meet him before he hunted down Sigma. Then 2001-Sigma told him Sun is dead. Then later Seohae also said Sun is dead. That gave him the idea to bring a vest. So when he finally met up with Sun, he gave him the vest.

If no one told him Sun is dead, he would probably never bring a vest and Sun would actually be dead. His original plan was only to meet Sun so he can give him additional instructions–which I believe to be the location of the bunker and to meet him at Asia Mart later that night.

Remember also what Taesul said, the future is already here, you just do not know it. Since everything in the time bubble is happening simultaneously and is constantly changing, the future that was yet to happen already arrived. If there was no time bubble and instead there is a timestream branch, then the future will never arrive. Yes, this is yet another proof that there is only one timestream in the Sisyphus universe.

He knows him well. When Eddie took over his company, it only proved to him how Eddie thinks and what his ambitions are. When Eddie showed all his feelings, Taesul was not even surprised.

But let’s go back to the scene in the underground facility. When Seohae was going to take care of Eddie Kim, what did Taesul said? Paraphrasing: he is probably going to the surface, he is not worth it, there is no time. “There is no time”? They can easily deal with Eddie Kim and then use the Uploader. They have plenty of time in the world because they can simply travel back at any given point in time.

Why then did he stop Seohae? If they stopped or killed Eddie Kim, after they shoot Sigma, Seohae will disappear. Remember that scene? But instead because of Eddie Kim, Seohae stopped disappearing. That in itself is a clue. It opened up a possibility wherein Eddie was able to force Taesul to give the code for the Uploader, this was why Seohae stopped disappearing.

Taesul need this very moment to do the last and most important piece of his plan. He entered in the code, time locked it, and probably included other conditions. Once that was done it was time to shoot himself. He also need for Eddie Kim’s greed to ensure the laptop survives. Just like Taesul, we can safely assume that Eddie ran away with the laptop and discovered Taesul time-locked the Uploader code.