Harrys kidnapper has sold him to a carnival freak show where he is billed a s Hargo the Alien, and his transmissions from The Big Giant Head are a huge hit. Harry tells Garvin, his boss, that he would like to go home. His family is probably searching for him and putting up posters. Garvin says if his family cared, they would be here by now and, besides, hes bound by a contract.
Mary has been named Dean of the School of Arts and Sciences. She moves into a much nicer office and takes Nina with her. Sally informs everyone, that tonights the night shes losing her virginity to Don. Dick jumps to the conclusion that since his girlfriend is the Dean, hes Dean. Dick struts around campus on a power trip. Later, Don and Sally dance a smoldering tango around his apartment, and he carries her piggyback into the bedroom.
With Marys promotion to Dean, Dick quickly finds that hes being perceived as Mrs. Albright. When Mrs. Dubceks grandson starts running a lemonade stand in the neighborhood, Tommy and Harry open their own stand, but have no success. When Sally learns that Don has had other women in his life, she makes a huge project of tracking down all his ex-girlfriends. Mrs. Dubcek tells Harry and Tommy that when kids sell lemonade on the street, its cute, but when adults do it, its creepy.
Dick is obsessed with collectibles from a fast food restaurant while Tommy becomes the mascot of his high school basketball team.
Since Mary became Dean, Dick feels shes been neglecting him. Hes even more unhappy when he learns hes about to have a new officemate: Dr. Jennifer Ravelli, a comparative literature professor from Harvard. Officer Don has a new partner (Eric) and when Sally finds out hes unattached, she insists on playing matchmaker. Dick is smitten with his new office mate.
Dick and Mary agree to date other people. Dick decides he should date his office mate Jennifer. Meanwhile Harry, Sally, and Tommy team up to create the ultimate room.
Don takes Sally bowling and finds her unorthodox style a bit alarming. Mary blames herself for losing Dick and tells Nina that shes really blown it. Dick tells Harry and Tommy it seems that the less available he is, the more Mary wants him. Frustrated that Mary has no clue how to win Dick back, Don sneaks away with Harry and Tommy to go bowling, leaving a puzzled Sally behind.
When Sally learns that Playpen Magazine is coming to campus and will pay women $600 to pose naked, shes ready to sign up. Sally tells Dick her plan and he supports her. Nina reminds Mary that she herself posed naked 20 years ago. Tommy is completely smitten with Alissa, his partner in biology lab. Harry struts around the apartment naked. Sally tells Don about her plan to pose naked and he forbids her to do it.
Mary is busy planning her annual New Years fondue party, but Dick cant understand why this holiday is such a big deal. Harry is having a huge New Years bash at the bar, and Tommy volunteers his services a s party coordinator. Dick becomes depressed when he realizes that everyone he knows has had a productive year, but hes accomplished almost nothing.
Chaos ensues when the Big Giant Head, switches Sallys body with Dicks. Both Dick and Sally are completely freaked out. Harry immediately puts in a request for them to be returned to their original bodies, but theyre on a waiting list. Harry and Tommy are intimated by a couple of tough-looking guys who spend a lot of time at the bar. Sally as Dick quickly manages to alienate Mary, while Dick as Sally does the same with Don. Harry tells them that if they dont work together, theyre going to lose Don and Mary.
Dick receives a letter inviting him to a Solomon family reunion in Indiana. Dick invites Mary to accompany the aliens to the reunion. Tommy feels compelled to remind Dick that these people are not their family. Things start out well at the reunion with everyone getting acquainted. Things get heated when the family believes Dick has come to town to reclaim what was his.
The aliens are introduced to the concept of paying income tax. Dick enlists Marys aid in filling out the forms. She informs him that he owes nearly $10,000 in taxes. When Sally realizes that there are numerous tax deductions for home businesses, she decides to open a hair salon in their apartment. The Solomons soon find out they are going to be audited.
The aliens and Mrs. Dubcek start feuding because she wont get their plumbing fixed and they wont pay their rent. When Sally tells Don she wants to get out of the apartment, he thinks she wants him to propose. Vicki Dubcek has come back to live with her mother and shes ready to resume her relationship with Harry. Harry goes downstairs to live with Mrs. Dubcek and Vicki. Tommy gets himself assigned to detention so he can ask his lab partner Alissa out on a date.
Mary confides to Dick that Chancellor Stevens seems to be avoiding her. Dick leads Mary to the conclusion that their co-worker Judith is after her job. Dick tells Mary about a mysterious document that Judith is hiding in her desk, and Mary becomes obsessed with getting a look at it. They break into Judiths office and Mary is hauled off to jail. Harry wins a pile of money on a riverboat casino.
Vicki tells that she wants him to be the father of her child. When Harry shares this news with Dick, Dick reminds him that his child may turn out to be a large purple tube. Sally announces that shes looking for an apartment, and Dick isnt happy about it. When Tommy refers to Alissa as his girlfriend, Harry says hes crazy, but Tommy insists its true. Dick believes hes loosing control of the unit.
Dicks grant application has arrived just as Dick is opening a chain letter. He has no idea how a letter could give him luck and Mary observes that belief in chain letters is a silly superstition. He polls the aliens for their thoughts on the subject and Tommy says its totally ridiculous. Dick and Mary are at a hockey game and Dick finally tears up the chain letter. Immediately Mary is flattened by a hockey puck.
When Nina leaves Dicks grade reports on the computer and he has no idea how to retrieve them, its clear that hes computer illiterate. Vicki has been trying to get pregnant for a month with no success, so she and Harry visit a clinic.
Mary is concerned that she and Dick communicate well, so they go to a New Age couples retreat with Harry and Vicki. Sally catches the eye of a tough-looking guy and soon, hes sending flowers and asking her out. Mrs. Dubcek identifies him as Sammy The ButcherMarchetti, and Sally, is swept away by the idea of being a Mafia girlfriend. Tommy, starts calling himself The Nephewand lets Sammy know hes available to run errands or whatever Sammy needs.
Dick, Harry and Tommy realize that their apartment has become a wreck since Sally moved out. Tommy, in search of an extracurricular activity, decides to work on the Zephyr, the school newspaper. Mary gives Dick the phone number of Cathy, her maid. Tommy accepts the position of editor on the Zephyr. Hes surprised to learn that August, his ex-girlfriend, also works on the paper.
When Don reminds Dick that his birthday is May 5, Dick orders the other aliens to throw him a surprise party. Dick is approached by Charlotte who first claims to be a housewife auditing his class and then says shes actually a reporter from the Cleveland Plain Dealer working on a story on greatness, however, she is not as she seems.
When Dicks co-worker, Professor Strudwick, gets a lot of attention because of his new book, Dick is secretly overcome with envy. Dick is determined to write a better book, until Harry reminds him that the publicity surrounding such a book would reveal him as an alien. Tommy goes to Alissas house for dinner to meet her parents. Alissas father is none other than Dicks rival, Dr. Strudwick.
When Sally, Harry, and Tommy barely miss being hit by a falling chandelier at a local restaurant, they feel as if their near-death experience has made them view the world in a whole new way. Dick is irritated that the other aliens pity him for his lack of enlightenment. Desperate to fit in, Dick signs up for a faculty field trip to Mount Digney and is determined to have a near-death experience if it kills him.
Harry gets a transmission from the Big Giant Head: the mission has received a sub-standard evaluation, and the B.G.H. is on his way to earth to check things out. He arrives on Earth and gives himself the name Stone Phillips.
Tommy reminds everyone that they're inches away from having their whole mission cancelled, so they'd all better shape up. Stone is sitting around watching TV soap operas. When he hears about Tommy's upcoming prom, he invites himself. Later Stone makes a pass at Mary, and she goes flying from the room. Tommy and Alissa are voted prom king and queen. Vicki gives birth.