Sherlock Holmes Chapter One

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

This achievement is missable, and is earned during the main story case 'A Gilded Cage'. You will unlock this story case shortly after uncovering Sherlock's room and completing the reconstruction there, which is automatic whilst progressing through 'A Mother's Love'. I strongly recommend you make a save before starting this case!

As a quick aside, there is another missable achievement you can combine with this one during this case:



For this achievement, progress through this main case until the very end, after you've filled out your mind palace, and can make your deductions to conclude the case. You need to ensure that you select the following conclusion selected in your mind palace, before giving anyone the incriminating photograph (you can change your mind right up until handing over if you make a mistake).

You will want to go for the animal-friendly conclusion here. After you've filled out your mind palace, and can make your deductions to conclude the case, you need to ensure that you select the following conclusion (you'll get all the clues for it by getting all evidence at each location, and providing evidence to all key persons



Speak to Imogen Gilden once you've secured this conclusion in your mind palace, and the achievement should unlock.