Mary

I hope they reveal the "engagement" next, so that Da Rim can join in the jealousy. :P

Isn't kissing when you switched bodies a bit weird? It is like kissing yourself.

They are half siblings - they have the same biological father. The sister is the ML father's affair child that he just brought home one day.
(Step siblings would mean they only became siblings by their parent marrying, but have no biological relation.)

The sister is so vile. I though that not inviting the FL was bad, but episode 2, just wow.
I really hope they do not try to “redeem” her like a lot of kdrama do. What she did is absolutely unforgivable.

When the "fiancé" was nagging her about not breaking up because she would be divorced before getting married ... I wish she told him she could just become a widow instead. What an asshat.

Half brothers share a parent as in they are biologically related, while stepbrothers are just connected by their parents' marriage - no blood relation.
Kathryn is probably implying that Sunwoo Hae's father was having a second family way before his mother died...

I didn't see her either, but since everything else follows the story, I would bet they will show her setting the fire next episode.

It's a Korean confection, kinda like taffy.

The evil rich girl probably set it. You can see it in the recap of the original story in episode 1.
— ML and FL meet when she nearly falls into the water
— The evil SFL confronts the FL and throws water into her face
— Jealousy sweet potato scene with the SML after he saves her from bandits
— SFL sets fire and the ML saves the FL
— Wedding

As you can see we are still following the novel even if the new FL is bringing a twist into it.

She is kinda living the meme “Mission failed successfully”. The more she wants to get rid of him, the more he falls for her. :)

Seeing how much the ML likes her crazy personality, I am really surprised how his relationship with the original FL was supposed to go. She seems way too calm and normal for him: he would be bored to death with her.

The re-do meeting between the ML and the novel's FL did not go as planned. LOL

It is neither. When you say "I am this close to losing it" you usually indicate “how close” with your fingers: you hold your index finger and your thumb about an inch (or less) apart. This is supposed to indicate that you are very very close to losing your reason due to anger or annoyance. Venus just used the emoji to symbolize this.

The childhood connection trope is really not very popular on MDL and a lot of people are frustrated that it appears in almost all kdramas.

I hope Kim Won Hae and Lee Yoo Joon also return, so that the whole cold case team can be back.

In my opinion, making her hate the company was a risky strategy. Instead of placating her with money and covering themselves with her signing a non-disclosure, they made sure she despises the company as much as her ex. Especially, since they made it impossible for her to find another job in the field.
If the FL had a different personality, this would have made her want to take revenge. And she had more than enough proof of her relationship (phone messages, photos, etc.) to drag KS and his rich wife (and consequently the company) through the mud in the yellow press. Which is exactly the thing they were trying to avoid ...

"2nd point, I guess, is about FL herself. She is not someone to quit her job for, which she puts everything for just a cheater."
How would the ML (who decided on the strategy) know that, though. It is not like they tried anything but the most extreme method. And transferring does not make you "someone". She did get moved to another team, so what's the difference to getting moved to another city instead.
But really, a non-disclosure agreement would be the most logical step.

What I don't understand is why they did not just transfer her to a branch in a different city or offer to pay her a generous severance pay if she quit. I'm sure she would have been more than happy to get away from her cheating ex. And both ways would be legal, easy and most importantly not completely inhumane.
Also, they pretty much ruined the ML with this. He was all okay with doing it and felt absolutely no regret until he fell in love with his victim. And who knows how many others he did something similar to. How are we supposed to root for them now???

About the reveal at the end of episode 10...

FL was in a relationship with him for years (and was expecting them to get married) before he went to the US for training, where he met SFL.

Don't forget, he also seems to have distanced himself from his family: because they disapproved of his cheating or for them not being posh enough in front of his rich in-laws.
It is really infuriating that the writer seems to want us to feel sorry for him. Ugh.

He is a real scumbag, but he is not the murderer.