Jack Klugman plays another loser here (after Joey Crown in A Passage for Trumpet, in Season 1 and Jesse Cardiff in A Game of Pool in Season 3), a bookie who can’t take the money off of a kid who bets it all on a horse that loses, then gets the comeuppance himself when his boss finds out about it.
When he’s called to the mat he gets a telegram that his son, fighting in Vietnam, is wounded, he loses it, and he sees a vision of him as a younger boy (played by Bill Mumy, It’s a Good Life, Season 3), where they make amends for everything they wanted to say to one another, and then he makes a deal with God to take him instead of his boy.
The next thing we see is the boy, grown again, shooting at the gallery where he and his dad met that fateful night, reciting lines that they would tell one another, so it looks like the bargain worked and the youngster’s life was spared.