Sherlock Holmes Chapter One

There are spoilers in this solution (in spoiler tags).

This achievement is missable, and is earned in the side-case 'Iron Coffin'. It can be started by eavesdropping on two women inside the Police Station. You need to have completed 'The Muse From Abroad' main story case, or you won't be able to eavesdrop on these individuals and accept the side-case.

I recommend you make a save before starting this case, just in case you mess up (although you can reload multiple autosaves if you’re prompt). As a very quick aside, there is another missable achievement in this case that can be combined with this one, with a solution below. You may think it'll void this one because of its description, but you can actually earn this achievement easily without voiding the below one, as the Pipe is not a suspect, just an informant. Just be sure to change exclusively for this achievement, and then immediately change back into your police clothes



For the majority of this case, you will be dressed as a police officer (see 'Lawful Neutral' solution linked above), but for this achievement - and JUST for this achievement - you must be dressed in dirty/street clothes to speak to an informant 'The Pipe. Essentially, you are following the 'Thinning the Herd' challenge. Clues will point you to this informant around half way through the case, and takes place in the Miner's Market once you've eavesdropped on some people on Clay Street (Miner's End).

I recommend saving before speaking with The Pipe. Then, speak to 'The Pipe' whilst dressed in (a) vagabond rags or (b) worker 's apron, as well as equipping either putting the (c) eye bandage or (d) bruised makeup. Wearing such clothing, this achievement should unlock Multiple options work.

As a final reassurance, this won't void 'Lawful Neutral', as the Pipe is not a suspect. Just be absolutely sure to change back into police clothes when you're done before speaking to any key suspect, especially Felicia, who is soon after.

The below is a good video reference of this case if you're stuck at any point (credit to 'Playthrough for fun)'.