Using a character from a novel

[littlebillie]

Just wondered what the legal premise is using a character from a story ie a Dickens character where he characters are expanded on I'm not planning to rewrite the story though

It shouldn't be a problem legally - Dickens is out of copyright. There are plenty of precedents - Wide Sargasso Sea is a retelling of the first Mrs Rochester's story, there have been sequels to Pride and Prejudice, reworkings of Emma, follow-ups to Gone with the Wind etc. It could be a nightmare in terms of the readers who love and are extremely knowledgeable about Dickens...

I just revisited a book recently and thought there's a big story to be told here

Isn't this what all Fan Fiction is?

As a PP said, if the original book is out of copyright (can be complicated depending on the jurisdiction [some jurisidictions seem to be intent on losing the point of IP law), any joint authorship and whether in the UK is contains Peter Pan) then I understand the character(s) can be used or indeed a full sequel or prequel using the character(s) and setting can be written.

Good luck.

Nelly Dean in WH has a novel ( modern) written from her POV it just covers a different time span to the original.