My take on the discussion Aslan and Edmund have after his rescue from the White Witch.

Two sisters fight for the fate of Charn; one would drag all to ruin, one would save it. Events just prior to Jadis' sealing herself away in the sleep-spell, waiting for the Magician's Nephew.

Why Jill has such difficulty with dark, underground places, and how Eustace reminds her of how to overcome that fear.