I haven't played The Last Express, so excuse the possible misguided jugment here, but Gabriel Knight 3 and The Dagger of Amon Ra, did feature some randomness in overhearing conversations and witnessing certain events only if you were there at the right time, n'est pas?
Of course, aside from that similarity, Dagger of Amon Ra is pretty much a painful experience in almost every other aspect so don't consider this an actual advice to try it
.
GK 3 on the other hand, is a pretty decent game, maybe even great if you fancy supernatural mysteries and don't mind the graphics' ugliness (
away).