Edit: From the comments, it seems you only really need the dialogue in Volume 2 and 3, so replaying from there should be fine and still get you the achievement, but I've left my Volume 1 choice in, in the case it's important.
I want to, first of all, say I don't take full credit for this entire solution as many people discussed parts about it in this thread
, so I want to thank them.
Now, this achievement comes down to, as far as I know, ALL of your interactions with Agent Ikeda in the game, and you need to hit a certain number of criteria to have her show up at the party in Volume 4 Chapter 2.
Now in order for your changes to save and progress through to Volume 4, you must
play from the point where you made a different dialogue choice. So if you made a different choice after the break-in at the old man's house in Volume 2, you have to play from there.Volume 1
There's only one major interaction here, but the bad part, it's right at the start. Most people seem to either have gotten this right, or managed to have gotten the achievement without going back to this dialogue (luckily, I, unfortunately, had to start a new save).
Now I won't say these are the exact
dialogue choices you need to follow, but the general theme of them is advised. My choices here were:
- Could I ask for yours?
- Agent of ..?
- I'd like a pony
- Proprietary info
You'll get an Uh oh... appear on-screen after Ikeda talks. This is the general thing you want to appear in most of her dialogues.Volume 2
There's one major dialogue here, and that's after visiting the old man. First of all, follow the guide to get this achievement:
Again, not every dialogue choice here is probably vital (a lot is still unconfirmed about all of this), so follow this to be safe:
- You're no Elliot Ness
- Personal Friend?
I remember getting a text prompt about annoying her or striking a nerve here, so I feel like is probably important.
If you followed the route for the achievement above, you'll have a unique dialogue prompt:
- Old guy should be glad
This will be a mistake and reveal you were there, I don't think any prompt after is important, but I went with the next
prompt - Wha.. You'll get a text prompt suggesting she's suspicious.
Finish out the Volume after this, there is another small dialogue section, but from what comments are saying, however you tackle this next section/what your answers are don't seem to be what makes an impact.Volume 3
There are 2 dialogues in this Volume, the one after the train heist I don't think
is of major importance to the achievement, but I will list my choices anyway, just in case it is:
The rest in this dialogue doesn't seem to make any difference or cause any text pop-ups. So make whatever choices you see fit.
Now for the final part, make sure you steal the HDD so chip dies and follow this dialogue choice:
Edit: It seems the only bit of dialogue that matters here is saying Awful... So the rest choose what you want
- Not starting again
Redmond will mention extracting here, and if all has gone right, he should say he's not sure you've convinced her though, or he will say you could've done better.
- Too bad
After this, she will show you the picture of Chip's body. Choose the
option first (I don't remember the wording) and then choose Awful...
Note: You don't need to do this next bit, it's just a way of checking whether she will show up or not.
If all has gone right, just before you go to the party in Volume 4, go up the ladder and talk to Redmond. Ask about Agent Ikeda and the Proof she has. He should say he has to lie low for a while as she's in London. If he says this, go to the party and you'll get the achievement after talking to the hostess. If not, you likely need to go back and get multiple dialogues right again as the ones you did weren't enough.
Well, that was a very long set-up. I hope this helps, and if there is any wrong information or anyone finds more surefire answers that are needed (so dialogues that impact this only), then please comment below so I can update the solution.