Board Thread:Skyrim/@comment-108.238.224.19-20130331211734/@comment-2602:30A:C0EB:9960:3CE7:6C:81CE:7F80-20170921074006

You have to be a member of the thief guild and talk to the two people in ragged flaggin that give quests. Vex and the other guy. Only Then will Mallory include the shadow mark dialog