After making sure that you have a Fragrant Branch of Yore in your inventory; you can run back towards the entrance to Things Betwixt; but instead of going up the hill, look right for some stone archways instead.
Head through here and you should chat to Benhart the NPC who’s resting on the ground with the giant blue sword. Speak to him then head inside and approach the stone statue.
Use your Fragrant Branch of Yore on the statue to free the woman known as Roseabeth. Speak with her fully (until she offers to go to Majula ) and then offer her your worst armor/anything you’ve got a duplicate of for the trophy/achievement.
Note: If you’re looking to complete Benhart’s story-arc then we recommend you speak to him right after releasing Rosabeth from her statue form. Exhausting his dialogue will push him on to the next area.
Before pulling the lever, enter the cells in the lower level and kill the enemies inside. After pulling the lever the cell doors up above will all open up and drop even more of those pesky poison Goblins onto the ground.
Pick them off with any sweeping melee weapons or area-of-effect spells to get rid of them quickly as a Basilisk will appear in the door by the lever. Kill this creature and then open the cells near the stairs in front for an [Estus Flask Shard] and a Bonfire . Eventually; the door at the top of these stairs will open and you’ll be in the next area of the game - Shaded Woods .