Writer Lynne Truss chooses the creator of Alice in Wonderland, Lewis Carroll.

Famous for the Alice books, Carroll was also a brilliant mathematician and early photographer.

But his reputation has been clouded by allegations, never substantiated, that he was a repressed paedophile.

Lynne and presenter Matthew Parris try to discover why, despite the millions of words written about him, Carroll still remains a mystery.

With assistance from biographer Robin Wilson.

Producer: Jolyon Jenkins

First broadcast on BBC Radio 4 in May 2011.