Follow Marcus' lead and swing the cage back and forth to free yourself. Head to the right and climb the big ladder. Remove all equipment from Marcus before you continue because he will leave and Zidane, Vivi and Freya will join.

Head into the castle and up the stairs. Go down and then up the circular stairs to the 3rd level. Go up through the double doors. Search the purple candle and try to move it then go through the passageway that opens.

Jump onto the spinning bridge and when you reach the other side, jump back on to get to the 2 chests on the ledge. Inside them is a Tent and an Ice Brand.

Continue downward until you come to the bottom, then go through the double doors. Inside you must fight Zorn and Thorn.

After the battle, Mosh the moogle will be there. Head back up the stairs. At the top, you'll have to fight Beatrix (Alexandria Castle) one last time.

Afterward, Beatrix will join you and she and Freya must take on a Bandersnatch. Zidane and the others flee back down the stairs but must fight 2 Bandersnatches and 3 Type C black mages.

When you get to the bottom Steiner will go back and then another Bandersnatch will attack. Meanwhile on the upper level, Beatrix and Freya must take on 2 more Bandersnatches themselves. Steiner will then join them and assist in taking out another 2 Bandersnatches.

When you flash back to Zidane and company, head down. Go back up through the doors and meet Mosh again to get a letter. Then go back and out the bottom exit this time. As you make your escape you'll be attacked by Ralvuimago.