The minute they step down off of the steps to the path on the main gate, several winged spirit demons are spawned from a black pool at the other end, which is your immediate destination. It's prudent to be near the pool to fight them as if one succeeds in picking up Yorda, that pool will be the destination. So run along the path toward the other end. They'll try to attack Ico and Yorda on the path, but if Ico and Yorda are running, they should be able to stay ahead of their attackers until they reach the other end. The spirit demons may get a bit closer when Ico and Yorda round the corner on the path but they can still make it. Once they arrive at the black pool, destroy the spirit demons, which should not be too difficult. Have Ico climb the ladder and call the princess up as well. She'll likely be abducted if he doesn't. Walk through the doorway and go over to the lever on the other side. Pull the lever to lower the drawbridge below inside. Note the sword in the alcove, which Ico doesn't need, as he's already carrying one. Move to the ladder and descend. Call Yorda at the bottom and wait for her to climb back down, then take her through the door and walk straight forward onto the newly lowered drawbridge.

Once across head to the left of the entrance to building housing the fallen chandelier. Walk along the pathway and note the rope that you pass on the way to the block at the end. Pull the block even with the first stone column that juts out from the wall. Climb up onto the box, then jump onto the column and have Ico pull himself up. Turn and face the taller column to the right (on the other side of the rope). Take a step and jump across to the taller column. Turn toward the rope and cut it. Have Ico walk off the end of the stone column and call to Yorda. Have them walk together to the right and then turn left to enter a familiar area. The stairway on this side ends abruptly, so have them run around to the other side and head straight down the stairway. You'll hear the black pool opening up as they start around. There's a black pool at the top of the stairs and several flying spirit demons around it. They'll probably get Yorda and carry her down to the other black pool below, which is in front to the desired exit point. Actually this time it works to your advantage and you may not have to fight these guys much at all. Once Yorda is carried off, run down the stairs and have Ico go to the black pool and pull her out. He may have to clear out some of the spirit demons first, but when they have the opportunity, they can run on ahead through the open Idol Doors just past the black pool.