Switch (1975)

Pete and Mac do a literal song and dance as they help an old vaudeville hoofer try to figure out who took several shots at him onstage, killing his dance partner.

Pete becomes a rather overage soccer goalie (Robert Wagner, though he looked younger, was 47 at the time of filming) in order to figure out who killed the team's previous goalie and how (the killer uses a camera with a special attachment which shoots a poisoned dart).

Mac reacquaints himself with a number of people he hasn't seen in years after he and Pete reopen the case of a glamorous actress who was murdered 30 years earlier.

Soem interesting underwater (swimming pool) footage highlights this episode as Pete and Mac -- in full business suits and at their ages (over 70 for Eddie Albert) dive in to defuse a nuclear bomb threatening to take out a society party and much of Los Angeles to boot. This episode was broadcast on August 6, 1978 (possinly its first run) just before the TV news announced the death of Pope Paul VI.

Pete tags along when Mac attends a reunion of his old police buddies, but the event takes a dark turn as someone is killing off the attendees one by one.

Ryan is forced to protect a kingpin's son at a golf tournament, otherwise Malcolm's life is forfeit.

The series began a summer run (ironically, enjoying its best ratings since the first season and tremendously better than it had done in the fall) with an episode about kidnappers grabbing the brother of a photographic model -- the brother is a veterinary student specializing in large-animal surgery, which he is to be forced to use to remove diamonds from the hide of an African rhinoceros recently imported to Los Angeles. Watch very fast for Natalie Wood bidding her then-husband Robert Wagner (Pete) goodbye from a bathtub at about the 10th minute.

The near-ultimate in budget-conscious "bottle shows" (all but two scenes are filmed inside Malcolm's Bouziki Bar; Pamela Bellwood and two firemen are the only guest actors; and much of the show is in flashbacks) finds Pete, Mac, Malcolm and Maggie trapped inside the bar with a very pregnant murder witness while mob hit men search unseen for a way in. Some sources give this episode's air date as August 13, 1978, when the show was run off as a summer series (and did very well in the ratings).