The crux is a difficult drop. To get it you must get glowoo from the hard Crota raid. Then you wait until the next week. Once everything resets put on glowoo and do the hard raid. You [b][u]must[/u][/b] do the hard raid [b][u]first[/u][/b]. You [b][u]can't[/u][/b] do the normal and then the hard. The hard raid [b][u]must[/u][/b] come [b][u]first[/u][/b].