The show focused on Jonathan Hart (Robert Wagner), a rich CEO, and his wife Jennifer (Stefanie Powers), a freelance journalist. In their spare time, the two pair up as amateur detectives, with some help from their butler Max (Lionel Stander). Each episode focused on a crime that they were currently trying to solve. Most of the cases they worked on dealt with murder, robbery, kidnapping, and espionage.
After five seasons on the air, the show was canceled due to low ratings in the last season. In 1993, the cast reunited to make eight made-for-TV movies.
This show provides examples of:
- Abhorrent Admirer: Many episode focus on Jonathan and Jennifer dealing with some form of this trope. Jonathan especially had to deal with two separately insane stalkers who tried to murder Jennifer, and the second only knew him for like five minutes before she fell for him!
- Amateur Sleuth: Jonathan and Jennifer.
- Benevolent Boss: Jonathan and Jennifer are both this to Max, and Jonathan is frequently shown to be a very understanding and courteous employer to the people who work for Hart Industries.
- The intro scene to one episode shows Jonathan working on the docks, unloading cargo and speaking to the other workers. It turns out it's his dock, he's undercover, and he's investigating rumors that the men are overworked. He finds out it's true, and kicks the crap out of a dock foreman who threw a punch at him when he pointed out the men were overworked and needed a break. The dock supervisor shows up in a company limosine, tells Hart that he doesn't know who he's dealing with, and he'll never work on these docks again. Jonathan then delivers the Wham Line.Hart: Neither will you. I'm Jonathan Hart. I own Hart Industries. Now get your big fat fired ass out of my limosine.
- The intro scene to one episode shows Jonathan working on the docks, unloading cargo and speaking to the other workers. It turns out it's his dock, he's undercover, and he's investigating rumors that the men are overworked. He finds out it's true, and kicks the crap out of a dock foreman who threw a punch at him when he pointed out the men were overworked and needed a break. The dock supervisor shows up in a company limosine, tells Hart that he doesn't know who he's dealing with, and he'll never work on these docks again. Jonathan then delivers the Wham Line.
- Don't Tell Mama: A Valentine's Day Episode had the Harts tangle with a diamond smuggling ring operating out of a gourmet chocolate shop. The head of the group is the son of Mrs. Bittersweet, the woman who runs the chocolate shop, and he's frequently covering up the smuggling ring's activities from her. She's actually the real head of the ring, and those cover-ups were her son trying not to disappoint her with his blunders.
- Early Installment Weirdness: In the first season, Max's opening-credits narration ended with the phrase: "I take care of them, which ain't easy, because their hobby is ... murder!" As the show isn't actually about happily married serial killers, subsequent seasons modified this to "...because when they met, it was murder!"
- Evil Aunt: In one episode, the Harts must deal with a woman and her boyfriend who're after the valuable baseball card collection bequeathed to the woman's nephew (her dead brother's son). This is despite knowing her sister-in-law and nephew could really use the money.
- Evil Old Folks: Mrs. Bittersweet, the head of an international diamond smuggling ring operating under the guise of a gourmet chocolate shop.
- Fourth Date Marriage: The flashback episode "Two Harts Are Better Than One" shows that Jonathan and Jennifer only knew each other for a few days in London before he proposed.
- Friend to All Children: Despite not being parents or ever considering having kids of their own, the Harts get along great with kids. Jennifer especially donated a lot of her time sitting bedside with a girl who'd been in a coma for several years.
- Genre Blindness: A lot of episodes are about the Badass of the Week trying to outsmart the Harts but they seem to never have heard of all the other bad guys crossing the Harts' way whose successes were questionable.
- Happily Married: The Harts are so much this trope that one episode revealed three associates of Jonathan established a betting pool on the night of his bachelor party, wherein they wagered cash on how long the Harts would remain married. One guy, who bet they'd stay together for five years but split before ten, took it upon himself to make it look like Jonathan was cheating on Jennifer to split them up. Every attempt to sow marital discord failed miserably, but the Harts decided to pretend they were splitting up to figure out who was going to all this trouble. Jennifer never believed for a second that Jonathan would ever think of betraying her.
- Idle Rich: They are when they aren't solving crimes.
- Made-for-TV Movie: Eight of them.
- MAD: Har To Har
- Mystery Magnet
- Mystery of the Week
- Nice Guy: Jonathan and Jennifer are honestly two of the best people you could ever have as a friend or ally. Many times the Mystery of the Week involves a friend of their's that's gotten into some form of trouble, and the Harts do everything they can to try and help them. Provided the friend isn't Evil All Along.
- One-Hour Work Week: Though Jonathan is the CEO of a very large company, he seems to spend plenty of time solving crimes.
- Pretty in Mink: Jennifer often wore a fur when they went to a special event.
- Spiritual Adaptation: The show is basically The Thin Man with the gender roles reversed.
- Stalker with a Crush: A recurring plot point. Either Jonathan and Jennifer would attract one of these.
- Undying Loyalty: Max is completely devoted to the Harts, and likewise they would do anything to help him if he asked or needed it.
- Wheel Program: NBC attempted to use the 1993 reunion movies as an anchor for a new Friday Night Mystery Movie series, but the idea didn't take off.
- You Look Familiar: Both Stefanie Powers and Lionel Stander co-starred in separate episodes of Wagner's earlier series It Takes a Thief (1968).