The show is back and the game is on. Review by Brandon Wolfe With the exception of HBO’s Curb Your Enthusiasm (currently winding down a six-year dry spell), no series on television resurfaces as infrequently as the BBC’s Sherlock . Due to the bustling Hollywood careers of leads Benedict Cumberbatch and Martin Freeman, the stars need to perfectly align for another season of the detective drama to come to fruition, resulting in a three-year gulf between seasons (broken up only by last year’s trifling one-off " The Abominable Bride "). For a series whose seasons only run a scant three episodes (albeit each 90 minutes long), this leads to an irregularity comparable less to other television series than to Halley’s Comet. Sherlock is the star that burns twice as bright and an eighth as long. Get it while you can because it won’t be around for long, and its return is far off on the horizon, if it arrives at all. “The Six Thatchers,” the fourth season premiere (and only the e