Stone's Fall - Iain Pears

Industrialist John Stone, Lord Ravenscliff dies after falling out of his window, his death is kept from the papers for several days. After it is finally reported, his wife, Elizabeth, hires a journalist ostensibly to write a biography of her husband, but really to solve a mystery left in his will. What that journalist, Matthew Braddock uncovers, is more shocking and more far-reaching than either of them expected.
Like An Instance of the Fingerpost, his previous novel, this is a story wrapped in another story, itself containing another narrative. What starts as Braddock's account of his investigation in London in 1909, flows backwards through history into Henry Cort's account of his involvement with Stone in Paris 1890 and finally into Stone's own memoirs of Venice in 1867, unravelling until the shocking, unexpected and utterly brilliant (in a dark kind of way) final page.
The ending has a real sting in the tale, so even if you find the first section slightly dull and heavy going as I did, stick with it, Cort's section and then Stone's (which fills in a few gaps in Cort's account, as his does for Braddock's) picks up pace and really throws the reader into a mystery that will stun.