You can get this achievement after helping ratbag with his mission to start the process of getting this achievement you will encounter a specific cutscene in the game where a gollum watches you from afar then after your charecter and wraith are finished talking in the cutscene a new mission will apear the new mission marker will have a yellow outline with what looks like a circle which can be found on the map these are going to be a little side quest story which is wraiths memories which is needed to unlock more wraith powers as you progress the memory missions should appear on the map each time you complete one i hope this helps give a better understanding of how this achievement works and how to get it