The “X” designation refers to the number of clones in this 100% Cabernet Sauvignon. You have to search for the richness—buried so deeply now—but it's there, like a pirate treasure of blackberries, black currants and cassis liqueur. Hard, thick and resistant now, it's framed by astringent tannins and a dryness that's almost arid. Charles Krug clearly built this wine to age, and there's no reason it shouldn't. Your window begins in 2018 and should last a very long time.