It deserves a sixth star just for the ending, but I won't say anything about it.

I swear, it didn't occur to me that I was reading such a hilarious comedy until page 20 or something: it just seemed a bit awkward. When I realized the theatrical quality of what I was reading, all those guys' subterfuges to keep their conscience clean while doing the most rowdy and outrageous (or just plain illegal) stuff--I started laughing at every page turn.

John Steinbeck was quite simply a genius.