Clarification: Edmund and Lucy are still living with Eustace in the introduction, but once the story begins they'll have joined Peter and Susan in London. From there the story will progress as foretold in the summary that is, admittedly, weak. I did only have 384 characters to work with though, so you'll understand my plea for forgiveness from you, treasured reader.
Introduction
"Do you reckon we'll ever return?"
"I might die if we don't."
The conversation from that afternoon echoed in Lucy's mind as she lay awake in bed. Edmund and Eustace had accomplished quite an impressive feat by nicking a bag of sweets that looked suspiciously like the ones aunt Alberta kept hidden in a box at the bottom of her wardrobe. They had finished them together, also an improbable turn of events seeing as Eustace would have taken them for himself not so long ago. But that would have been before the Dawn Treader, and none of them wanted to think of the fact that they would never see such a time again. However this seemed to be the very thing occupying their minds as they finished the sweets in a silence that was slowly turning dense with nostalgia. Afterwards Edmund had sat on the bed, amongst sweet wrappers strewn about and uneaten candy, and made a great show of looking as miserable as Lucy felt.
"I miss Narnia."
"I miss Caspian."
"Do you really, Lu?"
"I really do."
And with that Lucy began to cry. She hated showing weakness in front of anyone, let alone Edmund. She was the youngest you see, and no matter how much she grew, she would never be any older to him.
The entire ordeal had tired Lucy, and so she had turned in early that evening. That had been a mistake, she thought, as she lay reflecting on the events of the day. She couldn't go to sleep, it was not yet dark, and so she missed instead. Free time, or time not spent doing meaningless tasks, was time spent missing Narnia. Missing Caspian. Just missing as a whole.
Just missing as a life.