“Oh, Shenandoah” is the name of this penultimate episode of Aaron Sorkin’s series – and perhaps there’s a clue in that title, for those old enough to remember the wistfulness of that one-time hit song. Regardless, what we do know is happening tonight is that Will (Jeff Daniels) is jailed for refusing to reveal his news source. And his boss, he’s preparing for a fight, too…