Étude in black (aired 17 September 1972): It's anything but music to his ears when a symphony conductor's mistress plans to go public with discordant facts about his extramarital activities. The greenhouse jungle (aired 15 October 1972): A horticulturist concocts a phony kidnapping scheme with his nephew to get to a trust fund. But when the nephew turns up dead, Columbo suspects the uncle of collecting a different kind of greenery--and of murder. The...