Floor 15

Move Zelda east over the spikes, then down and around to a triangle glowing tile.

Stand Link on his triangle glowing tile to switch positions.

Move east, then north across the sand pit, and fight the Geozard. Use the Whip to snatch its shield, then dodge its attacks and slash it.

Move west to a block. Push it west, then north onto a ground switch.

Stand on the square glowing tile, and have Zelda stand on the identical tile on the other side to switch positions.

Have Zelda stand on the other ground switch to lower the spikes previously crossed.

Reunite Link and Zelda. Push open the big doors.

Grab the small key inside the chest behind the doors.

Head back to the center via the drop-off ledge.

Move Link and Zelda through the west corridor.

Hit the distant switch across the pit with Link's Boomerang to extend a bridge across the sand pit.

Warp Zelda to the nearest Phantom Eye (a type of enemy that acts as a temporary platform).

Walk Zelda south, west across the bridge, and south, past spikes, into a secluded hall.

Stand Zelda on the circle glowing tile.

Move Link to the identical circle glowing tile in the central room to switch positions.

Before moving Link, warp Zelda back across using the same Phantom Eye.

Move Zelda to the southernmost switch, which lowers spikes.

Move Link out of the secluded hall.

Use Zelda as a shield for Link against boulders so he can reach two switches.

Have Link and Zelda step on both switches to extend a bridge across a gap.

Get Link to the two switches across the sand pit in the far northwest corner.

Get Zelda as close as possible to Link.

Get caught by a Phantom Eye. Stand on the sand pit. Warp Phantoms will appear and sink into the sand pit.

While the Warp Phantoms are out of commission, warp Zelda to you since the Phantom Eye is still on you.

Kill the Phantom Eye.

Have Zelda and Link stand on each of the two switches in the northwest corner. This opens the door in the north central corridor.

(Alternative strategy for the northwest corner switches: Use the Boomerang to stun the Phantom Eye, then use the Whirlwind to blow it across the sand pit before warping Zelda there.)

Get both Link and Zelda to the north central corridor (warp Zelda to the Phantom Eye near the staircase).

Head upstairs after unlocking the door.