Brilliant detectives like Sherlock need a sidekick who can keep them tethered to the real world, a partner and confidante who can keep their lives from feeling like the plot of a comic book. Watson was logical, and clinical, and his brilliance lie in the realm of reality, unlike Sherlock who often let his mind stretch out to the realm of impossibility. Together they're a legendary crime solving duo, two men responsible for bringing London's criminal underworld to its knees.