Gramos Coffee Bar (underground, sub-level -1)

You'll descend into the bowels of King's Cross Station—past the Harry Potter shop madness—and suddenly find yourself in a proper coffee operation that takes itself seriously. It's not your typical station kiosk situation: Gramos actually knows what they're doing with espresso machines and grind settings. The kind of place where you'll spot regulars who've timed their commute around their flat white, and where the queue moves with the efficiency of people who've genuinely perfected their craft. It's cramped, it's underground, it's absolutely worth the detour.