Great Forgotten Scene
Fallon starts a fight while waiting to get an injection to avoid being recognized by another inmate.
Fallon fails to recognize a prominently displayed picture in his cell as that of his 'wife', but quickly covers up by saying something about the haircolor being different.
Cody, with a sinister smile says "Your little trick didn't work", and pauses;
Another cellmate says "Yeah, doc says you still gotta take your shots"; then everyone laughs.
Both Edmond Obrien and Cagney milk the scene for all its suspense and tension.
It's the only time in the movie I was rooting for Fallon not to get unmasked by Cody.