The Schirmer Inheritance — Eric Ambler

It wasn't anyone's idea of a glamorous first assignment at a white show law firm. George Cary, former WWII bomber pilot and newly minted lawyer, was given the ignoble task of going through the tons of files on the Schneider Johnson case, just to make sure nothing had been overlooked. But, as luck would have it, George did discover something among the false claims and dead-end leads that made this into more than just another missing-heir-to-a vast-fortune case. And what he found would connect a deserter from Napoloeon's defeated army to a guerrilla fighter in post-war Greece, and lead Cary himself into a dangerous situation where his own survival will depend more on what he learned in the army than anything he learned in law school.