3rd Rock from the Sun (season 6)

Mary's wealthy sister Renata Albright (Megan Mullally) has donated a large sum of money to have an extension built onto Pendelton University, but Mary knows that it is in fact a spiteful gesture designed to quite literally block the sunlight into her office. To retaliate, Dick schemes with Mary that he will woo Renata, win her, and then break her heart. Meanwhile, Sally and Harry are given ten thousand dollars by Renata to convert their house into a teen center.

After playing assistant to a magician at a child's birthday party, Dick decides to himself become a magician, with Sally as his assistant. They become a huge success, performing shows night after night at a local club, but show business soon starts to eat away at their offstage relationship until they hate each other. Meanwhile, Mary joins a defense class after being mugged in the park, while Harry joins the class as the man in the padded suit that everyone attacks.

Dick and Mary visit a psychic together, who claims that the pair are from two different worlds and predicts that Dick will one day up and leave Mary. Horrified at this news, Dick decides to find a replacement boyfriend for her, settling on a man called Gary; who thinks he's actually being offered Dick's position of physics professor. Meanwhile, Sally and Harry decide that if the psychic really knows that they are aliens, then they must kill her, but in a way that isn't possible for her to predict.

Dick has bought a new camera, with which he makes Mary angry, by constantly taking her picture against her wishes. As a result, Mary decides that the two need some time apart. Meanwhile, Sally's coat is ruined when Harry wears it out in the rain, but he claims that the Channel 10 weatherman said it was going to be sunny. Sally marches down to the station and tries to convince them to pay for her coat, but it soon becomes apparent that Sally is excellent at predicting the weather, so they give her the position. Dick, however, is worried that Sally's spot on prediction of the weather will attract unwanted attention and so, when she discovers that Rutherford is to be hit by tornados, he orders her to report otherwise.

Nina accuses Dick of knowing nothing about Mary, so in an attempt to prove her wrong, when Judith walks into the office announcing that she has two tenth-row tickets to a Gordon Lightfoot concert, Dick claims to already have front row tickets. Of course, he doesn't, and so attempts to find a pair of front row tickets before it is too late. Meanwhile, Sally tells Chaz, the Channel 10 anchorman, that she would like to start presenting the news instead, and so he agrees to let her interview Lightfoot in the company's box at the Rutherdome; but really, he intends to seduce her.

Mary's mother Martha (Elaine Stritch) arrives in town and Dick decides to tell her what Mary really thinks of her - that she ruined her childhood. Angry, Martha tries to attack Dick and falls over, ending up in hospital. When Dick goes to visit, however, Martha tells him her side of the story, and a deeply moved Dick takes her side and promises to tend to her during her recovery. Meanwhile, Harry and Sally get a nasty surprise when throwing junk into the time space portal - a new alien (Mark McKinney).

Dick discovers that Mary has been receiving elaborate love letters from a mystery man named 'Scoochie' and confronts her about it. She reveals that she has been receiving them for years but has no idea who Scoochie actually is, so Dick pretends that it has been him all along. This goes wrong, however, when the real Scoochie arranges to meet Mary at the Medieval Festival. Meanwhile, after another alien unit operating in Ohio wins an award over the Solomons at the Alien Award Show, Sally and Harry make it their mission to track them down, and eventually move in with an Amish family, who they believe to be the other unit, since they are so different.

Mary is having trouble dealing with seeing Dick transform Liam into a monkey, which Dick did to stop Liam doing the same to the Earth's population. Dick consults the other Solomons and they decide that the best approach is to deny everything. Mary meets with Nina and Judith, who confess that they've always believed there's something suspicious about Dick. Nina thinks Dick is an international terrorist; Judith is convinced he's a psychopathic serial killer itching to place Mary's head in a box.

When Dick and Mary next meet, she demands that he tell her the truth about himself. Dick admits that he and the others are in fact aliens, from outer space. Mary's first reaction is anger at being lied to again, but when pressed to think back with that added information, she flashes through disbelief, shock, surprise, brief nausea, then slow realisation and ending with finding it sexy to be dating a "spaceman".

Elsewhere, the local store has been robbed and Sally catches Don hiding in the frozen foods freezer, which he admits that he did because he was scared. Harry takes a different line and asks the shopkeeper Sam out on a date, but later runs into her working at a posh restaurant, where she instructs him to call her Samantha. Confused, Harry believes that he is dating twins, so confused high jinx ensues as he tries to juggle them 'both' on a date, attempting to keep her (Sam) from herself (Samantha) - finally losing out altogether.

At the end, as they sit out on the roof discussing the day's events, Harry receives a transmission from the Big Giant Head telling them that after a complaint from Liam about their changing him into an ape, their mission on earth has been terminated. They are to pack immediately as their earth bodies will be terminated in a couple days. They're utterly shocked and dismayed at the news, none wanting to leave to go back home.

The Solomons are struggling to take in the news - they have been ordered back home due to Dick's transgression with Liam. Dick's first instinct is to ask Mary to come, so he takes her to the planetarium before breaking the news to her that they are leaving, and asking her if she will join them, and she agrees.

Meanwhile, since admitting his fear to Sally, Don has decided to quit the police force and open a muffin store, but Sally is disgusted by this career choice and decides to whip Don into shape - and turn him into a hardy police officer.

At home, Harry and Tommy are attempting to organize a farewell party for the aliens, but have no money, so they decide to max out their credit cards and not worry about paying the bill, since they'll be halfway across the galaxy - they even hire Elvis Costello to sing Fly Me to the Moon.