Tim muddles with history when his trip back in time botches the sale of Manhattan Island in 1626.
Martin turns a squirrel into a human.
Martin loses his sixth sense to Mrs. Brown, which puts his identity in jeopardy.
Martin becomes the blood brother of a race horse when a mosquito bites the animal after biting Martin.
Using his time machine, Martin brings Leonardo da Vinci into the present to help him with a mechanical problem.
Mrs. Brown steps in front of Martin's Personality Altecator and becomes a crook.
While Martin is clearing himself of Virus M, Tim accidently contracts it.
In an attempt to get home, Martin changes himself into a liquid and is lapped up by a dog.
Martin's nephew crashes on Earth and must adjust to the new life.
When a gypsy puts a curse on Mrs. Brown, Martin is unable to reverse it because his antennae are out of order.
Spies kidnap Tim.
Cologne causes Martin to stiffen up in a department store and he is mistaken for a mannequin.
Martin inadvertently activates a worthless robot.
Martin's telesensory transmitters short out causing him to televise everything he sees.
Martin helps a photographer; guests Michael Conrad, Nicholas Colasanto.
To inherit, Tim goes back in time to add Martin to the family.
In an effort to seem important, Alvin boasts that he is working on a top secret space project with Martin.
After being demoted to writing obituaries, Tim uses Martin's time machine to get the scoop on a big story.
Honorary deputy Mrs. Brown (Pamela Britton) becomes a zealous guardian of law and order. Guest star: Victor French. With Bill Bixby, Ray Walston.
Martin's duplicating machine makes a permanent copy of Tim.
Martin (Ray Walston) studies aging on Earth and meets two dear little ladies (guest stars Lurene Tuttle and Nydia Westman) with a talent for larceny. With Bill Bixby.
The time machine malfunctions, causing Jesse and Frank James to appear in Tim's kitchen.
Martin (Ray Walston) accidentally captures a foreign space ship and its attractive female pilot (guest star Jill Ireland). With Bill Bixby.
Martin uses his new invention, a benevolence bulb, on Brennan.
Martin bottles himself for the trip back to Mars but winds up in Bagdad, where he is mistaken for a genie.
Martin (Ray Walston) overcompensates for his gold-free Earth diet. With Bill Bixby.
Tim (Bill Bixby) takes allergic Martin's (Ray Walston) memory pills and gets mistaken for a rocket scientist.
A malfunctioning molecular reassembler switches Martin's (Ray Walston) body with Mrs. Britton's (Pamela Britton). With Bill Bixby.
Martin's (Ray Walston) "futuroid" camera shows Tim (Bill Bixby) being wed within 24 hours to an unknown bride (Yvonne Craig).
Martin and Tim travel back to 1925 where Tim is chosen for the lead in a silent movie.
Tim and Martin escape from jail but are set upon by riverboat thieves.
Tim and Martin are arrested by Brennan's great-grandfather when they time-travel back to 1849.
Mrs. Brown loses her breadth and to protect her, Martin pastes her onto a picture canvas.
While using the time machine, Tim and Martin unwittingly intercept the delivery of the Magna Carta to King John.
Martin must find a way to recover an ancient Aztec Chest which contains a record of a former earth visit.
Mrs. Brown becomes irresistible to all men, including Martin, after she gets a Martian chemical on her.
Mrs. Brown (Pamela Britton) thinks Martin's (Ray Walston) music juice can turn her into a concert pianist. With Bill Bixby.
Martin (Ray Walston) mistakes a hobo (guest star Guy Marks) for a martian scout and introduces him to soap, water and a lovely widow (guest star Amzie Strickland). With Bill Bixby.
A family captures "martian" Tim (Bill Bixby) when he and Martin head to the desert. Guest star: Linda Evans.
Martin makes Tim invisible.
Tim (Bill Bixby) gets a secret message and becomes a spy. With Ray Walston.
Uncle Martin plans to hitch a ride home on an Air Force rocket.
A homesick Martin (Ray Walston) meets a sweet little old lady (Madge Blake) who could double for his martian mom. With Bill Bixby.
A botched rejuvenation process turns Martin (Ray Walston) into an infant. With Bill Bixby.
Tim and Martin (Bill Bixby, Ray Walston) set out to get retiring Miss Pringle (guest star Doris Packer) voted Teacher of the Year.
Martin tries to help a pickpocket go straight.
Martin competes with Detective Brennan.
Martin loses his identity disk.
Martin accidentally shrinks his ship.
Martin tries to curtail Mrs. Brown's generosity, only to cause her to become a miser.
The sound of a bad violin short-circuits Martin.
Martin's levitation finger is out of wack after he is exposed to the sun's rays.
Tim and Martin discuss deep-freezing children until they are older.
Martin's sneezing malady causes memory lapses.
Tim's Irish uncle visits and becomes convinced that Martin is a leprechaun.
Martin creates a disappearing machine which makes Detective Brennan disappear.
Martin uses a benevolence bulb to get Detective Brennan off his trail.
Cleo, the pet rabbit, eats Martin's vitamins and grows to be 6-feet tall.
Martin's subconscious goes out on the town.
Martin is upset over a neighbor using a rain-making machine and ends up tearing a cloud while trying to stop them.
A boy takes Martin's spaceship on a joyride and steals his electromagnetic neutron converting gravitator.
Tim accidentally duplicates Mrs. Brown and Detective Brennan.
A boy's silver braces cause him to acquire Martin's knowledge.
Martin's brain recorder has a serious malfunction, causing him to sing at a local coffee house.
Tim brings home an authority on Extra Sensory Perception.
Martin is transformed into a walking telephone after attempting to fix the TV antenna.
Mrs. Brown's nephew sees Martin's ship.
Indecision causes Uncle Martin (Ray Walston) to split into three separate beings with very distinct personalities. With Bill Bixby.
Martin's memory pill causes Tim to forget Martin, Mrs. Brown to forget Tim, and Martin to forget Mars.
Martin is afflicted with a disorder than causes his dreams to come true.
Uncle Martin needs dental assistance when his eye teeth affect his vision.
Martin (Ray Walston) gets a job at Tim's (Bill Bixby) newspaper.
Martin tries to help Tim get a promotion by feeding Mr. Burns his special stew.
Martin is chosen as the first "man" to go to Mars and Tim leaves a tape revealing his true identity.
Martin starts developing a resistance to gravity.
Martin develops a condition which causes him to start appearing and disappearing uncontrollably.
Martin makes Mrs. Brown's brainy niece (Marlo Thomas) beautiful.
Martin gets a Martian Vitamin Deficiency and causes people to spontaneously fall asleep.
Determined to keep his spaceship in flying condition, Uncle Martin takes a flight and is seen by Mrs. Brown.
Martin causes the latest toy craze with his antennas raised.
Martin accidentally over-electrifies himself for a return trip to Mars.
Martin experiences jealousy when Mrs. Brown's boyfriend comes to visit.
Martin must hide his ship from prospective buyers after Mrs. Brown puts the house on the market.
Mrs. Brown begins following Martin as part of her private investigation class homework.
Martin promises to get Tim an interview with a foreign leader.
Martin picks up a police broadcast, which lands Tim in jail.
Martin wants to stow away on a rocket to Mars.
Martin gives Tim credit for his paintings.
Martin levitates a new piece from the art museum.
Martin gets amnesia and forgets his true identity, causing him to use his powers in public.
Martin's powers are severely curtailed when sun spots flare up, causing him to disappear.
Uncle Martin (Ray Walston) prepares to return to Mars but a series of mishaps make his departure seem unlikely. With Bill Bixby.
To prove that money left to a cat rightfully belongs to an orphanage, Tim and Martin (Bill Bixby, Ray Walston) hold a seance.
Martin must remain invisible while Tim's cousin, Harvey is visiting.
Tim (Bill Bixby) must rescue a neighbor's child who was inspired by Martin's tales to scoot up Sunset Mountain. With Ray Walston.
Smitten with a coworker, Tim enlists Martin to get inside her mind.
Martin enlists the aid of a 13-year-old science genius.
Martin (Ray Walston) uses incriminating fingerprints for his driver's license application. With Bill Bixby.
Uncle Martin finds the material he needs to repair his spaceship only to find that the craft is missing.
Martin temporarily gives Tim the power to read minds.
Martin (Ray Walston) sets out to experience love at first sight. With Bill Bixby.
Martin seeks relief from a heat wave and lands in a loony bin.
Martin helps little Annabelle with a report about life on Mars.
An article about the space program gets Tim mistaken for a Russian spy.
When Uncle Martin comes down with a cold, the sneezing causes him to appear and disappear uncontrollably.
Martin plays matchmaker for both a dog and for Tim.
Newspaper reporter Tim O'Hara offers sanctuary to a Martian who has crash-landed on Earth.