Complex sentence: The "emergency" turns out to be a routine operation; the anesthesiologist turns out to be "Me Lay" Marston, an old friend of Hawkeye who works in a Japanese hospital/whorehouse.
Split into simpler sentences: The "emergency" turns out to be a routine operation. The anesthesiologist turns out to be "Me Lay" Marston, an old friend of Hawkeye who works in a Japanese hospital/whorehouse.