Title (4/5)

This isn't the most original title you could find throughout AFF, but I like the title for your story. I felt that it relate well to the storyline. Other than vengeance, you could try its synonyms as a title like maybe reprisal.

Description/Foreword (8/10)

You don't always have to use a scene for the description, trying to write a paragraph about the story would spoil less of the story itself. Otherwise, I felt that your description was too long. Next time, try to shorten it by writing a short and simple paragraph that summarize your story but doesn't spoil the entire story. There's a grammar mistake too. I just needed to point it out for some reason.

The knock of the door broke the enveloping silence, Jongdae muttering a low ‘come in’.

The knock on the door broke the enveloping silence and Jongdae muttered a low 'come in'.

Do stick with one tense. You're writing in past tense so muttering would be incorrect. I won't comment much about the foreword because it's just some greetings and credits, but I like how it's short and simple.

Characterization (17/20)

I can see that Jongdae cares about Xiumin, seeing from the way he reacted when he knew the Kim Minseok who is found deceased is the same Kim Minseok he worked with for a long time. On the description, Kyungsoo said that Jongdae wasn't accepting the fact and it had been eighteen hours. Well, it is normal that he can't believe it, I mean, people doesn't accept fact that easily. And eighteen hours isn't even a day. Based on Wikipedia, in the United Kingdom, people mourn over 6 months for their sibling, parents would mourn over their child 'as long as they feel so disposed', and widows are supposed to mourn over their husbands for two years. I think Kyungsoo is a rather straightforward character who accepts reality easily and isn't one to dream or fantasize. I do praise Jongdae for trying to forget Minseok as he asked Kyungsoo to find him a second assistance.

Meanwhile, I'm not much impressed by Jung Seoyeon's character. She seems like another typical character. I don't like how you explain about her personality in the prologue, that just revealed everything about her and reading the next chapters wouldn't be as interesting if the readers knew exactly how the character would've reacted. I wouldn't comment much further about Jung Seoyeon because the story hasn't progressed too far yet for me to judge her completely.

For the more minor characters like Luhan, I wouldn't comment too because they aren't making too much appearances so far. Luhan seems quite playful, though. In short, I really do like Jongdae's and Kyungsoo's character here, but I'm not sure about Seoyeon, she could use some more renovation for her personality.

Plot/Originality (14/20)

The plot aren't original, but stories doesn't have to be original to be good so that's alright but being original is way better. It's a shame that you revealed way too much already, it would've been more exciting if you had not. Because the story isn't finished, I can't have a say about how the story plot will turn out but so far, so good.

Rather than talking about the plot, I wanted to talk about the story itself. I think you need to do some research. I don't think detective agencies would give out flyers to hire a new detective, and I think that there would be at least tests for their physical abilities, right? And shouldn't agencies find out about her background to make sure she aren't paid to spy on the agency? Even though this is fictional, you should do some research when writing about factual stuff.

Mechanics (grammar, spelling, punctuation, etc.) (18/20)

I would like to point out a mistake that I think almost every writers here in this site do and that is the misuse of dialogue tags. I wanted to point this out in my previous review for Kookiesnkreamx3's story, but I forgot so might as well as put it here. I wouldn't talk much about it because to be frank, I'm not good at explaining things so here's a great article about it : Use and Miuse of Dialogue Tags. Please do note I'm deducting your score because I noticed a few grammar mistakes which is varied so I will assume it's just an error.

Flow/Pace & Style (6/10)

The flow is too quick. It has been two chapters plus a prologue and you have revealed the bad guy. It is also obvious who Agent 58 is. I would suggets you didn't point out these kind of fishy things on the first chapters so that the readers would stay curious and have something to anticipate for. I like your writing style, and there's no problem about your style at all.

Appearance (4/5)

I think the contrast of Jongdae in the poster is way too bright. I'm a graphic designer myself so posters and such really bugs me if they doesn't suit well for the story. It also bugs me why the picture used in the poster is of Jongdae holding a beer, I don't think that reflects anything of the story. The background has this kind of gradual effect which is nice but it seems weird when tiled up. For the story itself, everything was simple and nice.

Overall Enjoyment (7/10)

I was going to give a lower score, but through reviewing the story, I get more in-depth with the story and I like it better than before I started reviewing it. It'd be better if you give more suspense and mystery to the story, though.

TOTAL : 78/100 

Comment

I think you guys did well on this one and I should give you an applause for that. Good job! There's still room for imrpovement, but so far you guys are doing good.