The author Val McDermid's probably most famous for writing a series of books about a police psychologist called Tony Hill. They made it onto the BBC in the UK and are probably on some US cable channel if you look hard enough (they're called the "Wire in the Blood" series in the UK at least).
In this book, McDermid introduces an unrelated character, Jane Gresham. Gresham is a Wordsworth scholar who believes that Christian made it back to the UK after the mutiny and spilled his guts to (his school friend) Wordsworth about Blyth liking men rather than women. When a body that is similar to Christian's turns up in the Lake District, she sets off to investigate.
It's a daft story I know, but it rattles along at are fair old whack and if you like your thrillers slightly different, you'll probably admit that storyline is as odd as you've read in a while.