Jack Cassidy appeared in Columbo episodes on three occasions, but my favorite one was this episode dealing with "the Great Santini", his magician par excellence. Cassidy is starring at a nightclub/dinner club owned by Nehemiah Persoff. The club spotlights David Copperfield level magicians, and Cassidy certainly is able to pull in customers. But he is not making the money he should be. The reason is that he is being bled every week out of half his income by Persoff. The latter, a rather nasty blackmailer and creep, latched onto Cassidy secret. In World War II he was Sergeant Muller, a 21 year old Nazi fanatic who was in the S.S. and responsible for many atrocities. He is a war criminal, and Persoff will inform the authorities unless 1) Cassidy remains his star at the club, and 2) Cassidy keeps paying him 50% of his salary.
It is a running theme in detective fiction that killing a blackmailer does not count. In the "Sherlock Holmes" stories, Charles Augustus Milverton is killed by a collateral victim of his vicious business, and Holmes and Watson learn who she is but don't inform Lestrade (whose own attitude is, "Good riddance to the rubbish."). Here Link and Levinson came up with an interesting twist on this. We don't like Persoff, but we really don't care for the egotistical Cassidy either. He is all career, with a little left over for his daughter and assistant, and quite cold to most people. He also has fragments of his past beliefs that show up. He disapproves of his daughter's boy friend and makes a comment about the latter's genetics and background. He comes up with a scheme to give himself an alibi during his stage performance, using a trick or two to convince people he is far from Persoff's office. But he kills Persoff (who was typing a letter to the FBI regarding Cassidy's past at the time). In his care for the murder scene Cassidy takes the letter and burns it. He then sets it up to look like the unsavory Persoff was killed by underworld associates.
Enter the Lieutenant, who just can't buy the theory regarding the Mob rubbing out Persoff. Instead he soon finds the trail pointing to the one man with an alibi of sorts: Cassidy. And the process of chipping away begins, with the Lieutenant trying to get background on Cassidy and finding it a path that gets very vague about 1947 or so. "I find that you were the Great Darlington or the Great Washington.", he says to Cassidy. Cassidy says it was "Washington". Falk asks, "What was the first name?". Cassidy answers, with a sneer, "Martha!".
It is one of the best duels up to the conclusion, wherein Falk works some magic of his own to trap Cassidy, and present him with a past that won't disappear easily. But the best moment is actually Thayer David's. The portly and distinguished character actor only appeared in this one Colombo episode, and made the most of it: He is the owner of a magic store, and Falk is there to try to figure out what the trick is that Cassidy used for his alibi. David starts demonstrating a trick guillotine to Falk, and shows how to make it seem to pass through an object without destroying the object. Falk is fascinated but explains he is actually there to investigate Persoff's murder. Hearing about this, Thayer starts going into a mild diatribe against the deceased who was not popular among the magician fraternity because of his greed and trickery with contracts. Then after finishing it he suddenly realizes that he made himself look like a personal enemy of the deceased. He rapidly explains to Falk that he probably could get his brother-in-law and other people as alibis for his appearance at a family dinner on the night of the murder. Falk reassures him though that he was never a suspect. And then they discuss the possible explanation of the trick that Cassidy played.
A good episode with few slow spots, I think it was one of the best of the series.