So it all comes down to this. We review the season finale of “For All Mankind,” which puts the fate of the world in the crucible and makes us ponder the power of individual decisions when great systems seem intent on destroying one another. In addition to the dramatic life-and-death decisions, the plants at the bar are dead, Kelly has finished her essay, and we’re given a tantalizing look at what the 1990s might bring. Onward to season three! Host Jason Snell and Dan Moren.