The 'O' stands for nothing.

So before I say anything about the film, I was amazed and somewhat saddened to read so many negative comments about Spencer Tracy from other s. I love him so much, and think he has done such great work that to hear him described as 'lazy', 'smug', 'bland', 'despicable' etc. was a real shock. To me, he is the greatest.
Anyway, I love this script, I love the performances, the chemistry, and the general feel of the whole thing. Hepburn…