Sally, Harry, and Tommy return from the Home Planet with a surprise -- The Big Giant Head has sent his niece Janet, to be Dick's wife. Sally, Harry, and Tommy forget to cover up their landing site, and Officer Don thinks that aliens have landed in Rutherford. Tommy turns himself in for vandalism to keep Don from reporting his findings to the FBI Albright learns about Janet and breaks ups with Dick. Janet dumps Dick and hits the road in search of a younger, better guy. Although Janet's gone, Albright's going to need some time to think about taking Dick back.

Still angry after their split, Dick and Mary play a series of practical jokes on each other that goes a little too far--and then gets really nasty. After August says she's attracted to musicians, Tommy agrees to join Elman and Romano's rock band, and Harry becomes their roadie. Sally, incensed that their yoga instructor is attracted to Albright instead of her, wages an all-out war to make the guy want her.clip

Dick convinces Albright that since she hasn't yet told her parents the engagement's off, he should accompany her when she visits home. Soon, however, he's wishing he never ingratiated himself with the acerbic and dysfunctional Albright family. When Harry, Tommy, and Sally set out to help Nina move, Sally decides to move in with Nina instead--which lasts about an hour and half.

It's Halloween, and the thing Dick is most afraid of is going to the doctor for a routine physical, until back home, he and Harry face off against what seems to be a genuine ghost -- and turns out to be Mrs. Dubcek trapped in a crawlspace behind the wall. Sally and Tommy tangle with trick-or-treaters at Albrights house, leaving Mary to deal with the aftermath.

Dick can't understand why he's been putting on weight, until through dieting, exercise, and support groups, he realizes it's because he misses Mary. Tommy suspects that August is cheating on him (mostly because she is) and hires crime novel buff Harry to be his private eye. Sally's beloved tomato plant becomes fodder for Dick's diet.

Dick confronts the inadequacies of the American judicial system when he's called for jury duty. Sally is intrigued by a moody British artist named Seth, and begins emulating his lifestyle. Tommy and Harry volunteer for Albright's classroom demonstration, which entails communicating without words for five days.

Dick, friendless after his breakup with Albright, tries to shoehorn Officer Don into his life as best friend and constant companion... with mixed results. Sally shanghai's the slickly popular dancer Peter Connelly ("King of the Jig") to Johnny Foam's Cafe as a sacrificial lamb for her moody artist boyfriend Seth, and is horrified to learn that rather than the dark and tortured soul she fell for, Seth is a poseur... and a jig fan. Harry tries to get a job so he can buy Tommy some rollerblades, but lacking the required diploma, he must first weather the indignities of night school.

Tommy, despairing that he never gets to meet interesting women his own age, forms an attachment to Albright that incites Dick's jealousy. Sally gets an office job, then mistakenly thinks that her physical appearance is causing her boss' lewd advances and that she's sexually harassing him. Dick orders Harry to stop watching television for a week. After multiple attempts to sidestep Dick's order, Harry uses his spare time to actually start thinking, which annoys the family to the point where they give him back his TV.

Dick, Harry, Sally and Tommy are enjoying a sinfully delicious dinner of ice cream and cake when the discussion turns to the concept of sin. Tommy, who just studied the seven deadly sins in school, begins to list them and starts with 'pride'. Dick, however, downplays pride as an inherently human flaw. The other aliens present him with a series of examples, each illustrating that Dick is as guilty of the sin of pride as one could be. This holds true for the remaining deadly sins: anger, envy, lust, greed, gluttony and sloth. When it comes to sinning, it seems that all of the Solomon's are equally adept.

Dick bets Officer Don he can rehabilitate a petty criminal more effectively than Rutherford's justice system can, but the project is torpedoed by Dick's own inability to trust the guy. Albright decides to give away the dog Dick gave her when they were still going out, then regrets her decision to take Pepper to the pound. Tommy convinces Harry that writing his night school book report will be easier if he takes a few "shortcuts" -- which wind up taking far more time and effort than simply reading the book.

Harry finds an old wheelchair in Mrs. Dubcek's garage, and , while playing with it, Dick rolls down a flight of stairs and breaks his foot. Harry's thrilled that Mrs. Dubcek's daughter Vicky is back but horrified when she tells him she's practicing celibacy. Dick, confined to a wheelchair, is angry that the access ramp to his building at Pendelton is in an inconvenient location; encouraged by his physics class, Dick decides to fight for an additional ramp. Officer Don gets a job as a doorman/ bouncer at the Sin Drome, a local club, and revels in his newly-acquired power. Because he's under age, Tommy's barred from the Sin Drome by officer Don, so he goes in search of a fake ID. Dr Albright observes that Dick's crusade for another ramp is particularly foolhardy, because he'll be healed in a few weeks and won't need it. The university agrees to build another ramp; Dick is the winner, but he realizes he's made a serious mistake. And Harry, who's been frustrated from the moment Vicki arrived, is delighted when she decides she's been celibate long enough.

Dick realizes that he's beginning to be attracted to women other than Mary and that maybe he's ready to start dating. Tommy and Harry find a wallet and return it to its owner; at first they're pleased to have done a good deed but change their minds when Mrs. Dubcek says they should have been given a reward. Dick strikes out in his first attempts to attract women; Sally observes that women don't even have to be nice to men and they still grovel. Sally, Officer Don and Dick are at the Policeman's Ball, and Dick once again is having no luck with the women; Sally on the other hand, continues to attract men no matter how rude she is. Tommy and Harry show up at Rick's door (the whose wallet they returned) hoping for a reward, but Rick gives them nothing. DIck goes along with Tommy's suggestion that he place a personals ad, and he manages to get a date. Dick and Marry are mortified when it's revealed that she's the one responding to his personal ad.

When hordes of beautiful women start showing up in sleepy Rutherford, Ohio -- and seem enthusiastic about dating average joes like Dick, Harry, Tommy, and Officer Don -- Sally suspects that something's amiss. Before she can warn anyone that the women are really Venusians bent on dominating Earth, they discover her and force her to become one of them. The Solomon men embark on a countrywide search for Sally that ends at the Super Bowl, where the lethal lovelies have planned to unleash their most devastating weapon yet -- the ultimate beer commercial, designed to enslave mankind into coughing up the rest of their pricy consumer goods. In the supervixens' lair, the Solomon men seem defeated, but with the help of Sally, who only pretended to turn against them, and Venusian Mascha (Cindy Crawford), who's been won over by Harry's simple charms, Dick and company jam the commercial broadcast, explode the mother ship, and convince the supervixens that a career in modeling might suit them. Meanwhile, Albright and Nina's plans to attend the Super Bowl are thwarted when the Solomons steal their tickets to gain access to the Venusians, and back in Rutherford, Officer Don throws a decidedly low-key Super Bowl party.clip

Sally, intrigued by the "cult of pregnancy" and the strange bonding rituals that occur between its members, pretends to be pregnant in order to share the experience. Dick, initially skeptical, is entranced by the power of ushering in a new human life when he helps to deliver the baby of a woman in Sally's Lamaze class. Sally, however, is struck by the immense responsibility that motherhood entails, and vows to wait until she's ready before experiencing it for herself. Harry's pet from the home planet, Pickles, tracks him down across galaxies, with one big change -- he's assumed human form. Harry, initially thrilled at the reunion, decides that Earth might be too dangerous a place for his pet, and sends him home -- but not before Pickles has a close encounter with Mrs. Dubcek.

Dick's attempts to woo Mary back falter when the two of them become trapped in the university library for the weekend. Mary's initial resistance to rekindling her romance with Dick begins to melt because of (a) several magnums of cheap champagne, and (b) her realization that Dick was the only person to check her dissertation out of the library in the last fifteen years. Realizing Dick is missing, and fearing the worst, Sally, Harry, and Tommy break into Albright's house to look for him and, if necessary, physically drag him away from Mary. Instead, Sally winds up hosting a Tupperware party for all of Mary's friends, filling what had been a void in her life with her first experience at being a hostess.

Dick's attempts to woo Mary back falter when the two of them become trapped in the university library for the weekend. Mary's initial resistance to rekindling her romance with Dick begins to melt because of (a) several magnums of cheap champagne, and (b) her realization that Dick was the only person to check her dissertation out of the library in the last fifteen years. Realizing Dick is missing, and fearing the worst, Sally, Harry, and Tommy break into Albright's house to look for him and, if necessary, physically drag him away from Mary. Instead, Sally winds up hosting a Tupperware party for all of Mary's friends, filling what had been a void in her life with her first experience at being a hostess.

Tommy, tired of having to handle all of the "kid" duties (when in reality he's the oldest member of the mission), decides to retire. After he spends some time at a retirement home, he changes his mind, realizing that a big part of what makes you old is acting -- and being treated -- like your old. Dick, thinking that Mary is anguished because she never got a chance to fulfill her fantasy of becoming a torch singer, tries to help her to realize that dream. He learns that sometimes the choices we make between two career paths can be right on the money. In a moment of weakness, Officer Don steals a pair of Sally's panties, and makes a series of vain attempts to return them without being caught in the act.

Albright's father, George, visiting during a separation from Mary's mother, falls for Sally. Sally, in return, is intrigued by George's charming, old-school ways, his gentlemanliness, and his tales of World War Two exploits. Mary is both mortified by their mutual attraction, and fearful that this new relationship will lessen her dad's affections for her. Sally ultimately breaks things off with George to spare Mary's feelings. Meanwhile, Harry becomes a shock-talk jock at the Pendleton University radio station, but when his caustic ways spread from his listeners to Tommy, Nina, and Officer Don, he finds himself with neither audience nor friends.

When Dick attempts (and fails) to convince the students at Tommy's high school Career Day that physics is exciting, he reconsiders his choice of occupations. When Don lets him participate in a police interrogation, however, Dick learns that an education in physics can be used to succeed in a variety of pursuits -- for instance, baffling a suspect into confessing. Also, Dick orders Sally and Harry to get their own jobs. Harry tries his hand as a sympathetic bartender who ministers to his customers' psyches as much their thirsts. Sally becomes a research assistant for Albright, but concentrates more on buttering up her new boss than on doing thorough work, a skill that keeps her from getting fired when her shoddy translations cause embarrassment when Albright uses them in a speech.

After research shows them that they've failed in their mission of blending in as a normal, average American family, the Solomons strive to correct the problem by moving into a bland, beige apartment, dressing less oddly, and eschewing all that has made them stand out. Sally joins the tenants' association and becomes obsessed with making everyone in the complex adhere to the strict guidelines imposed by the group. When Dick meets a visiting professor whom Mary finds charming because of his eccentricity, Dick realizes he has erred in abandoning his individuality. He, Tommy, and Harry conspire to get Sally to hoist herself on the petard of her own narrow-mindedness, getting them all evicted so they can return to their beloved attic apartment.

Visiting professor Liam Neesam (John Cleese) is better than Dick at everything -- darts, physics, golf, cooking, and especially romancing Mary. Dick gets more and more frustrated until he realizes that the reason Liam's so good at everything is that he's an alien. Dick is on the verge of telling Liam that he's an alien, too, when Liam tells Dick he's decided not to vaporize the Earth because Dick is such a shining example of the human race, To save the Earth, Dick keeps his mouth shut -- no easy feat. Sally has a series of dating woes that come to a head when she thinks that even Officer Don has lost interest in her. Harry and Tommy try to help her find another man, but Sally, obsessed with finding out what has replaced her in Don's affections, presses on -- only to learn that his new mistress is a gal called "karaoke." Clip

Sally turns to romance novels for inspiration when it's time for her first kiss with Officer Don. Unfortunately, whether they try it on a windy, moonlit bluff or in the Solomons' kitchen, the kiss just isn't special enough. Sally becomes resigned to breaking up with Don, but when she goes to the police stable to tell him, the magical combination of horses, thunder, lightning, and Don's newfound forcefulness combine to make Sally realize Don's the guy for her after all. Dick is perturbed because the cafeteria lady charges him -- and only him -- for crackers. Realizing he has no control over her inexplicable dislike for him allows him to free himself from being bothered by her unjust treatment. Harry graduates from night school, and he and fellow classmates Mrs. DeGuzman and Larry reminisce about all the great times they had together during their ten-week enrollment.

Dick takes the family camping as a mission bonding activity. At the campsite, the family and Mary all become angry with Dick -- the family because he lies about bringing Mary along after he tells them it's "family only," and Mary because he tells her the family doesn't mind she's coming along. After they all cast him out, Dick goes off by himself and attempts to form a new society with a troop of Beaver Scouts he encounters. The Solomons assume Dick is lost and set out to find him. They (especially Sally, who resents her command being usurped) initially reject Mary's offers of help in finding Dick... until they realize she knows a lot more about the outdoors than they do.

Mary is asked to appear in a new Pendelton University promotional video. Dick whines until he is also allowed to participate. Unfortunately, neither of them shares the director's vision of what their "performances" should be like, and they are unceremoniously replaced by other "actors" (including Tommy). Harry volunteers to drive Nina to the dentist. A romance develops, but fizzles when the money Harry leaves under Nina's pillow as a Tooth Fairy reward is misinterpreted, and Nina, highly offended, throws him out. Officer Don gives Sally a key to his apartment, but his glee soon turns to gloom when she starts seeing the place as less of a love nest and more of a one-woman party zone that she can trash whenever she wants to. When Don calls her attention to her inconsiderate behavior, she apologizes -- but he still takes back his key.

It's the second anniversary of the first time Dick slept with Mary, and love is in the air. Dick decides to throw a party for himself and Mary, Harry and Vicki Dubcek (Jan Hooks), who's back in town and ready to pick up their romance where it left off, and Sally and Officer Don. When the family realizes that Tommy's been hiding some serious gourmet cooking skills from them, Dick insists that Tommy prepare a festive menu for the lovers. At the party, Dick realizes that Mary has no idea what they're celebrating, and he begins to have doubts about the future of their relationship. Just as Dick and Mary are settling their problems in one room, and Sally and Don are about to consummate their love in another, they're all interrupted by Vicki, screaming that Harry's been abducted by her psychotic ex-boyfriend, Randy (Phil Hartman), who's come to town to eliminate his competition by kidnapping him. In Randy's car, Harry receives a transmission from the Big Giant Head, potentially compromising the aliens' identities. (Season-Ending Cliffhanger)