There were basically two kind of episodes at work on MISSION IMPOSSIBLE. You either had the intense, complicated plot to overthrow some dictator ---OR--
you had a fun, outrageous plot to bring down some delusional kook. Here, look for the absolute outrageous, credit William Read Woodfield, who also did many stories for VOYAGE TO THE BOTTOM OF THE SEA. He had imagination.
One of the most popular actors on tv at the time, John van Dreeland, plays ultra greedy Prime Minister Durvard. He has the good fortune to have a fabulous uncut diamond found in his small country, and will be paid handsomely for it. However, the damn fool wants more --- so the IMF team concocts a plan to introduce him to a "diamond machine" (could you believe it!) that will crank out copies of the priceless gem ... and of course relieve him of the original diamond. How to con a con. Beautifully done.
You have to admit, in real life, there probably would have been quite a few high ranking individuals skeptical of this sort of crazy plan, even if they were crazy themselves, but Woodfield took the chance and its quite entertaining, more of a dark comedy in this case. Without too much surprise, future MI episodes would have a "money machine" and other duplicating devices.
Van Dreeland may have been an old friend of Martin Landau, as they worked together on many tv shows, such as THE TWILIGHT ZONE. Before this episode, he had a great role opposite Lana Turner in MADAME X (1966), and worked for many years at Warner Brothers tv on shows like 77 SUNSET STRIP and SURFSIDE 6. Those were the days.
Also in the cast is the man for all seasons, Woodrow Parfrey (as Henks), best as nervous, neurotic types or con men, roles he played many times on MANNIX. We all loved this guy! He was also a WW II hero, during the famous Battle of the Bulge.
Watch for the "cat" sequence, which nearly throws a monkey wrench into the crew's master plan. Best of SEASON 1, EPISODE 19 restored CBS/Paramount dvd box set (2006).