How do I write a novel?

The Moonstone (1868) by Wilkie Collins uses a collection of various documents to construct a detective novel in English. In the second piece, a character explains that he is writing his portion because another had observed to him that the events surrounding the disappearance of a certain moonstone might reflect poorly on the family, if misunderstood, and therefore he was collecting the true story. This is an unusual element. Most epistolary novels present the documents without questions about how they were gathered. He also used the form previously in The Woman in White(1859).