“The Grey,” the season two finale of AppleTV+’s alternate history series For All Mankind, is the best TV episode I’ve seen so far in 2021. It’s tremendously exciting, packed with game-changing moments, and full of character beats that hit perfectly. I haven’t seen a drama series have a season finale this good in ages. The entire second season, which is set in a world where the US and USSR colonized the moon in the 1970s, has built, slowly but surely, to what amounts to a Cuban missile crisis on the moon, as showrunner Ron Moore puts it. As the season nears its end, hostilities between the two countries ramp up on the moon, leading to casualties on both sides. That escalation of tensions reaches its apex in the penultimate episode, where Soviet cosmonauts overrun America’s moon base, killing several astronauts, some of them thrown out into the merciless vacuum of the moon’s surface after an explosion.