Reporter Tim O'Hara, while covering a flight of the Air Force X-15, finds a spaceship that contains a genuine martian. The martian is a professor who specializes in the planet Earth and now has to repair his spaceship before he can go home. (imdb)

There is dual girl trouble in the O'Hara household. George, the dog who Tim is looking after for Mr. Burns, is in love with Chloe, the dog from next door. Trying to get George and Chloe together, Tim falls for Chloe's owner, Marsha. However Marsha has had some recent relationship problems of her own. Howard Loomis, her boyfriend, took off to Mexico without as much as a goodbye. Because Marsha feels betrayed by Howard, she is now overprotective of Chloe and suspicious of all men, including Tim.

Martin comes down with a common cold, which is not so common but rather debilitating for Martians. Meanwhile Tim is sent to Trimbles Department Store to review their outer space exhibit.

Martin reads about a $2 billion space program, a program he knows is doomed for failure. Not wanting to see the American government waste $2 billion, Tim writes a fake letter to the newspaper which includes Martin's nighttime musings; Tim thinks Martin's mumblings are key to the flaw in the space program. Based on the fake letter, Tim writes a story criticizing the wasted $2 billion. Tim's masquerade is uncovered by the government, agents for whom think he's a spy working for the Russians.

Renowned scientist Professor Newton Jennings posits that life no more advanced than amoebas or jellyfish can exist on Mars. Martin helps Angela write a report refuting Jennings claims, which quickly gets her a failing grade. When Martin's attempts to reason with Angela's teacher, Miss Weaver, fails, Martin figures the only way to regain the upper hand and Angela's trust is to speak to Jennings and expose him as a fraud. However Jennings is brilliant but has one minor flaw in his calculation.

To get some rarefied air, Martin goes atop a water tower. Passersby, including the police, think he's a jumper and he's promptly sent to the psychiatric ward of the hospital. Martin thinks he can quickly exit the hospital by reading the psychiatrist's mind and tell him what he wants to hear. However the psychiatrist, Dr. Harvey Bonnett, has other things on his mind, like his troubled marriage. Ultimately, Dr. Bonnett becomes the patient and Martin the doctor.

Martin allows himself to experience an emotion foreign to Martians: love at first sight. He falls hard for Peaches Ancream, that being her real given name since her father had a sense of humor. It is also an appropriate name as she is an exotic dancer. Peaches and Martin hit it off, so much so that Martin wants to marry her after their first date. Peaches admires honesty more than anything else in life, the reason that she broke up with her last boyfriend, Police Officer Thorp.

Tim talks Martin into temporarily giving him a Martian power. Martin decides to give him the power of levitation for a 24 hour period. When he thinks the power practically useless beyond performing mere parlor tricks, Tim asks for another, to him, more useful power: mind-reading. (imdb)

When the junk men come by, they mistakenly empty Martin and Tim's garage instead of Mrs. Brown's, and in doing so take Martin's space ship. Mrs. Brown has no idea of the name of the junk yard, but there was a witness to the incident: Booboo, a neighborhood dog. Booboo, with the help of his dog friends and acquaintances, helps Martin track down the junk yard.

After using a stranger's fingerprints to get a driver's license, Uncle Martin falls under suspicion of being a notorious jewel thief. Martin and Tim set a trap for the thief employing good old Martian know-how.

Martin needs the hardest substance possible to repair his spaceship, the substance he has in mind is silibalt, an alloy of silicone and cobalt but one that has not yet been invented on Earth. To make some, he needs a cyclotron. Rather than destroy Tim's kitchen making his own, he decides to follow Tim on his latest interview at the university, where there is a cyclotron.

Tim is pursuing who seems to be the unattainable Cynthia Parker. Through reading her mind, Martin finds out that Cynthia is passionate about the classical arts whether it be music, literature or art, and she figures Tim is not, which is the truth. However Tim becomes everything she wants in a man. However this façade Tim fears is hurting Cynthia. Rather than hurt her by telling her the truth, he decides the best option is to find her her dream man.

The O'Hara's have new neighbors, the Richmonds, within the family being young Stevie and his grown up sister Jennifer. The foursome go on a picnic to Sunset Mountain, since Martin needs to pick up some bling, an alloy located there but that has not yet been discovered by humans. Stevie has a vivid imagination and likes to pretend he's from Mars, which intrigues Martin. That's OK with Tim, as that means he can spend time with Jennifer alone.

Tim's cousin Harvey is coming for a visit, which means Martin is going to have to go into hiding since Harvey would know that Tim has no Uncle Martin. And they have to keep Mrs. Brown away from Harvey since she would definitely spill the beans about Martin. Living in a small apartment, Martin can only keep away from Harvey so much, even if he is in his invisible state. And the sleeping arrangements become an issue. Those are not the only problems about Harvey's visit.

The stupidest idea Martin has heard of since he's been on Earth: Rosemary Willis leaving her cat, Max, $650,000 in her will. Morton Beanbecker, the lawyer for the estate, is threatening Tim with a lawsuit if he continues to editorialize about the stupidity of the will and deceased Rosemary Willis.

Martin can make it back to Mars since Mars has deviated from its regular orbit temporarily and is thus closer to Earth than usual. Martin has a 10 hour window of opportunity. Just as he is about ready to leave, he slips down the stairs and sprains his ankle, which also sprains his disappearing antenna. Mrs. Brown immediately calls an ambulance to the scene. When the ambulance physician takes Martin's vital signs, they rush him to the hospital since his vital signs aren't "human".

Something is causing Martin's metabolism to go haywire. In succession, he loses control of his levitation finger, he magnetizes his clothing, he levitates, he becomes electrically charged, he shrinks and then he disappears. He finds out the cause is an increased activity of sunspots, and on Earth there is no way to control their effects on Martians. After five days, the sunspots are still occurring and Martin is still invisible.

Martin and Tim are on their way to interview Professor Eugene Downey, the foremost expert on rocket fuel - Martin thinks the professor can assist in getting him back to Mars - when Martin is hit on the head with a monkey wrench. Martin gets amnesia from this concussion. He has no idea that he's a Martian, despite Tim telling him so. The only thing Martin and Tim can agree on is that Martin needs to go see a doctor.

Martin discovers that the long-time curator, Wilbur Canfield, is not happy. He has just acquired an expensive Egyptian piece for the museum, but the museum's board is questioning the authenticity of this acquisition. Canfield himself is now questioning his own abilities, as he feels he may be too old to do his work properly. The board calls in independent expert, Pietro Donati. Martin will know the piece's authenticity, if he can only get a look at it.

Martin uses his powers to create paintings for Tim to sell, to help him pay for some expenses. But when Tim takes credit as the artist, an art expert doubts the paintings are legitimate since they are all in different styles.

Martin tries to convince the president of the Inter-Galaxy Corporation to send a rocket to Mars, so he can stow away and hitch a ride home.

When Martin's antennae pick up the police radio, Tim tries to secretly get a newspaper scoop, but ends up being arrested for knowing too much about the crime.

Martin makes a big promise to secure an exclusive interview with a foreign leader for Tim with interesting results.

Mrs. Brown is taking a course on how to be a private detective and she decides to follow Martin around as part of her learning experience for her private investigation class homework.

Pete Dudley, a real estate salesman, convinces Mrs. Brown that she should sell her ramshackle of a house, which causes a problem for Tim and Martin, especially in hiding the spaceship. Dudley already has prospective buyers, Edgar and Emily Graham, who would be especially interested in the garage since Mr. Graham wants to make it into a workshop. When the Graham's show up unexpectedly for their first visit, Martin has to hide the spaceship.

Martin finds himself involved in a romantic love triangle.

Uncle Martin accidentally causes a citywide power outage while preparing for a return trip home to Mars.

Martin is responsible for causing the latest toy craze that everyone is obsessed with, while having his antennas raised.

Martin needs to fly his space ship, which is deteriorating due to inertia. Tim's fear is realized: Martin's flight is spotted as a UFO.

The Earthly environment is causing a vitamin deficiency in Martin. He draws on energy and vitamins from everything and everyone around him. The effect on things is for them to go haywire. And if people look him in the eyes, they will fall asleep since they are sapped of their energy. Martin needs some vitamins immediately or else he will grow weaker and weaker to the point of no return.

When Mrs. Brown's brainy niece arrives for a visit, Martin works his magic to transform the former child prodigy into a beauty.

In an electrical storm Martin gets an affliction called popsy. It causes him to appear and disappear uncontrollably. He needs to ground himself to cure it. Mrs. Brown accidentally completes the grounding and gets Martin's levitation power.