The detective achivement will be achived when you have found 13 secret places/ stashes. Secret places are hidden somewhere in the background in areas you visit. To find them you will need to drag your mouse over the background until your mouse cursor turns into a gate and says "Stash". It's like a hidden object game except you don't have an object to look for.. Though the game claims in the stats screen that there are only 12 stashes, there are actually 17.

The game lets you backtrack to any place you have visited before, so don't worry if you haven't gotten the achivement yet when you reach the end of the game.

1 Secret

1 Secret

1 Secret

1 Secret

3 Secrets

1 Secret

Druids' Shrine
1 Secret

2 Secrets

1 Secret

1 Secret

1 Secret

1 Secret

1 Secret

1 Secret

I hope the guide will help you get the achivement. Use it as a walkthrough or just as a guide if you missed any location during your playthrough. This guide was created just to guarantee the Detective achivement, so I migh have missed one location or so, feel free to point it out in the comments. But getting all the secrets is not necessary to 100% the game, only 13 is required.

Thanks for reading and good luck!

*Also thanks to Murphy's Lawyer for pointing out the stash in the Scadan Inn and contributing with a screenshot!