Simplify the following text for a Grade 8 native English-speaking person.
Original: He and the other three children are taken under protection of Mr and Mrs Beaver , but while the others are having an in-depth conversation about the arrival of Aslan , Edmund sneaks away to the White Witch 's castle , where he expects to be made a prince and later a king .
Simplified: He and the other siblings are protected by Mr and Mrs Beaver . But when the Beavers and the other three Pevensie children are having a conversation about the arrival of Aslan , Edmund sneaks away to the White Witch 's castle , where he hopes to be made a prince and later on a king .