As upscale care in New York shifts from urban locales in the early 1900s, Knickerbocker Hospital remains in the city to serve a mostly poor, immigrant population. Undeterred by high mortality from sepsis in a pre-antibiotics era, chief surgeon John Thackery pushes medicine’s boundaries, pioneering procedures despite his painful past and severe cocaine addiction. Dr. Algernon Edwards, recruited by hospital patron Capt. August Robertson, is the chief’s professional equal, but Edwards’ color skews Thackery’s opinion — until a chance discovery changes it. Co-executive produced by Steven Soderbergh, who directs the first season, “The Knick” is a sometimes-graphic drama, revealing racism and corruption while desperate people became operating-room guinea pigs.