Murder on the Orient Express: Why to see remake when we know how it ends?

An episode of Doctor Who in 2008, featuring Agatha Christie as a character, reveals 'who did it'

For the distinguished crime novelist PD James, Agatha Christie’s distinctive contribution to the genre lies not in thematic complexity nor stylistic prowess, but in the meticulous fashioning of mysteries. In her 2009 book Talking About Detective Fiction, James wrote that Christie:

… is a literary conjuror who places her pasteboard characters face downwards and shuffles them with practised cunning … Game after game we are confident that this time we will turn up the card with the face of the true murderer, and time after time she defeats us.

If James is correct, however, and the satisfaction of a