Spoiler alert: This post is part of an in-depth
discussion of Perelandra by C. S. Lewis, which will inevitably
reveal key plot points. You may well have a lot of reading ahead of
you.
In a cave deep underground on Perelandra, Ransom
defeated the Un-Man, killing the body of his foe Weston and throwing
it into an underground fire. After this, he slowly found his way
through the dark, subvenerean caverns, seeing sights there that were
not meant for humans. Finally, he fell into an underground river,
which swept him back to the surface, depositing him in a pool on the
side of a mountain. There, he spent some time recovering from his
injuries. One remained: a bite from Weston on his heel that would not
stop bleeding.
Once he had recovered sufficiently, Ransom descended to the valley
below, then ascended the great mountain on the other side. Though
reluctant to continue, thinking himself to be approaching a holy
place, he felt himself urged on. At the peak of the mountain was a
basin or crater, completely covered in red flowers, with a pool at the
centre. A coffin like the one that had brought him to Perelandra lay
there, open and waiting to return him to Earth. He also perceived two
spiritual presences with him.
Ransom recognizes the two beings as one is the Oyarsa of Malacandra
(known here only by "Malacandra"; he explains that "Oyarsa" is a title
reserved for one's own sphere) and the other is the Oyarsa of of
Perelandra. Today is the day that the latter turns the rule of the
planet over to the King and Queen. Such had not been possible on
Thulcandra (Earth), but here Ransom has made it possible.
The Oyeresu decide it is time to show themselves, and after a few
terrifying manifestations, they settle on humanoid figures, thirty
feet tall, expressionless and sexless, and glowing white.