The Last Judgement — Iain Pears

When art dealer Jonathan Argyll agreed to transport the Death of Socrates from a gallery in Paris to its new owner in Rome, he had no idea that such a worthless, nondescript painting would cause such a stir. First someone tries to steal it from him in a train station. Then the man he's delivering it to decides he doesn't want it--and is brutally murdered a few hours later. Now Argyll is stuck with a painting that only the most tasteless collector could love... and he finds himself right in the middle of a murder investigation. With the bodies piling up, he must investigate the dark secrets in the painting's past--before someone with truly horrible taste decides to put him out of the picture for good...