The structure of the play
The play has two narrative strands which finally meet. These are:
Chris's and Ann's attempt to persuade Kate that Larry is dead, so they can marry. Joe wishes to support them, but sees that he cannot; the attempt by George, then by Chris, to find out the truth of what happened in Joe's factory in the autumn of 1943.
A slip of Kate's tongue tells George of Joe's guilt, but he leaves without persuading Chris. Chris and Ann insist on marrying and Joe supports them. This drives Kate (who sees this as a betrayal) to tell Chris the truth. Ann's showing Larry's letter to her convinces Kate that Larry is dead. The letter also answers Joe's repeated question about what he must do, to atone for his crime. He cannot restore life to the dead, but he can give life (free from a sense of moral surrender) back to his living son, Chris.
Joe Keller is not a very bad man. He loves his family but does not see the universal human "family" which has a higher claim on his duty. He may think he has got away with his crime, but is troubled by the thought of it. He relies on his wife, Kate, not to betray his guilt.
Chris Keller has been changed by his experience of war, where he has seen men laying down their lives for their friends. He is angry that the world has not been changed, that the selflessness of his fellow soldiers counts for nothing. He feels guilty to make money out of a business which does not value the men on whose labour it relies.
Kate Keller is a woman of enormous maternal love, which extends to her neighbours' children, notably George. Despite her instinctive warmth, she is capable of supporting Joe in his deceit. To believe Larry is dead would (for her) be to believe his death was a punishment of Joe's crime (an intolerable thought), so she must persuade herself that Larry still lives. Joe sees this idea to be ridiculous, but must tolerate it to secure Kate's support for his own deception.
Ann Deever shares Chris's