Can't access Piercing the Veil 4/5

So a buddy and I got to the final part of piercing the veil. He had to go so i went on to do side quests until the following day. When i returned it seems i can't access the mission. The objective says enter the Exalted Terrace. When I Pin the mission it takes me to the abandon mine which seems like a dead end. The path looks like it should be clear from the south but after the sand storm it's blocked off. Anyone experience this and know how to complete the mission.