This is an angel roll then an inside turn (180 degrees. not turning outside, a backside turn if you like, but a frontside turn.) This forces the staff to do a quick half beat of forwards fishtail near your elbow and then the staff should angel back down the other way.
I think it might be useful to practise forwards fishtails are your elbows for this move.
It's quite useful to pinch the staff in your elbow for a moment during the turn and then release it into the angel roll. You have to have angel rolls VERY comfortable for this move.
In the video I show it in both directions and then connected up. It should be possible more continuously than this, but I have only just learnt it. (and without the falling over everywhere foot movement.)
http://tutorials.firestaff.net/tutorials/tutorial-videos/wmv/angel/angel-squared.wmv (Right click, save target as... )
Streaming Flash Video: