Spoiler Alert:
CBS’ “Salvation” illustrates the problem of a countdown. When a show has a significant, world-ending event on the calendar, it can only end poorly. The asteroid is coming and for two seasons of “Salvation” the main thrust of action comes from the reaction of people to the asteroid and the ineffectual efforts of the government, a rogue hacker organization and a genius billionaire to divert the asteroid from its course. There are plenty of amazing, thought-provoking episodes, especially in the first season. And then there are the dumb actions, mostly in the second season.

By the penultimate episode, none of that matters. Humans are doomed by the incoming asteroid. Old rich and evil people have made off with the show’s namesake spaceship/lifeboat for humanity and there’s nothing left to do but tie up loose ends, except “Salvation” is a TV show and needed a way to continue if it were picked up for a third season. (It wasn’t.) That’s when the writers decided it wasn’t an asteroid.

If you’re writing a series with an asteroid and you’ve built it up to the point of impact, you either need to end it with a bang or with the success of people over nature. In this case, “Salvation” decided to offer a vote of no winner and scuttle everything it had built up to the last episode, which was unfortunate because they could’ve gone out with a bang.