At first glance, the idea behind the new sci-fi movie “The Ditch”, which Warner Bros. just bought, sounds a lot like “Fortress II” (or hey, even the first “Fortress”) with Christopher Lambert — a sci-fi movie about a sci-fi prison that someone has to break out of or die trying. This time around, the good guy isn’t a wrongly imprisoned con, but a guard who is forced to help a terrorist escape the prison or die trying.