Is the robbery they're talking about, by any chance, the case of "the murder on the Orient Express" by Agatha Christie?
And... Was it really a murder? I mean, Shun looks like a good man and all, but "weathering" a financial down in another country doesn't sound a very legal thing to do, and the change in the attitudes of some of his friends..........
But what a shame: the station for the Orient Express in Istanbul (yes, the one where they got on the train) is no longer in service but I think it's still open as a museum or something...