The 2011 critics' preview DVDs for AMC's Breaking Bad, which launches Season 4 Sunday night at 10 ET, are subtitled: "Warning: Extremely Volatile." And, as usual with this sly show, it's an understatement...our journey with Walter, at this point, puts him approximately at Dante's seventh circle of hell (out of nine) --the circle known as "Violence," with its unhappy occupants of tyrants, murderers and squanderers...