“Puzzlelock.” From Ironside: Season 2, Episode 23 (52nd of 196 installments). First aired: 13 March 1969. Regular cast: Raymond Burr (Ironside), Don Galloway (Det. Sgt. Ed Brown), Barbara Anderson (Officer Eve Whitfield), and Don Mitchell (Mark Sanger). Guest cast: Simon Oakland (Mel Grayson), Dennis Cooney (Paul Dekes), Ned Glass (Benjie), Jocelyn Brando (Etta Gibbs), Gene Lyons (Commissioner Dennis Randall), Dabbs Greer (Thomas Gibbs), Alvin Hammer (Mush Shelby), Jennifer Gan (Chickie), Barry Cahill (Sgt. Miller). Writer: B. W. Sandefur. Director: Allen Reisner.

   It was a dark and stormy night when Mel Grayson murdered his wife. Sure, they’d had their disagreements, but for Mel it was time to leave their relationship — or more precisely, it was time for the wealthy woman to depart this vale of tears and leave all her worldly goods behind for him to enjoy.

   It’s no secret that he kills her. The first act shows how Mel meticulously executes his plan, cleverly establishing his alibis (yes, more than one) with sticky tape and by being punctual with a dinner date (which will prove his ultimate undoing, for his dining companion is an old friend from Mel’s time with the police department, none other than Ironside himself).

   No, this isn’t a whodunnit type mystery; it plays more like a highly compressed Columbo episode, in which the murderer’s cover story is slowly but surely worn away to nothing.

   Mel does deserve some credit for ingenuity, though. He uses the sticky tape to convince the servants that his wife is still alive before — and even after — he leaves the house for dinner, although she’s been dead for some time. (Watch the episode here.)

   He drags his wife’s body from the bed, but only after having changed her clothes to a nightgown, over to the French doors, pockets all of her expensive jewelry, leaves the house in the rain storm, furtively doubles back to their second story bedroom, and breaks the glass, with rain pouring over her prostrate form, making it look as if a burglar did it.

   So far, so good (for Mel, anyway) — but as the show progresses, we learn that he seems to have made two rookie mistakes. When he murdered his wife, Mel strangled her with her necklace, but most of the time women don’t wear heavy, expensive jewelry to bed; and then there’s that dry spot under the body. If a burglar had broken the window panes and killed her in the struggle, the floor beneath her should have been covered with glass fragments and rain water, which it isn’t.

   But were these really mistakes, or did Mel incorporate them into an even more ingenious plan to make a burglar coming from the outside look like a murderer coming from the inside? And is it more than just a coincidence that dwelling with the unhappy couple is the ideal patsy, someone who is always broke and always arguing with Mel’s wife, someone who can’t alibi himself on the night of the murder? All Mel has to do is feign sympathy for the poor sap while pointing Ironside & Co. in his direction.

   It looks as if Mel has pulled off the perfect murder — and so he has . . . almost.