At the end of the book, Monique's mother mentioned that James (Monique's father) would write her a lot of beautiful letters, so it's established that letters are a way in which James liked to communicate.
James could've also been very emotional and thought that a letter was a better way to express his thoughts in. It is a plot device, no doubt about that, but it's consistent with what's been established so far in the book.
James could've also been very emotional and thought that a letter was a better way to express his thoughts in. It is a plot device, no doubt about that, but it's consistent with what's been established so far in the book.