George Sunday (Ardal O'Hanlon) is a mild-mannered shopkeeper who has an "alter ego". Whenever danger threatens, he changes into the superhero "Thermoman" and rushes off to save the world. One day, Thermoman saves Janet Dawkins (Emily Joyce) from certain death when she falls into the Grand Canyon. He takes a fancy to her and decides that he wants to get to know her better. He tries to get to know her as "George", since he doesn't want her to know about his "alter ego". Things don't go quite according to plan, however. George soon has to reveal to Janet that he's really Thermoman. She accepts him anyway and the two end up living together.
George and Janet have a new addition to the family: Cassie. She can see into the future. However, shortly after birth, she has horrible premonitions that everyone on the Northern hemisphere is going to die! Meanwhile, Piers enters for ""I'm A Celebrity: Get Me Out Of Here!""
George and Arnie become the subject of an investigation by the Immigration Department.
When George buys a car and ups the offered price and then takes reponsibility for an accident that was obviously Piers' fault, Janet trys assertiveness training, which promptly fails.
Piers is frustrated by his lack of success with women and, when Mrs. Raven tricks him into thinking that a patient is his next date, he starts up a men's group to combat women. George is highly impressed by this, and trys it out on Janet, who is having none of it until George controls her mind and she becomes the perfect wife. He quickly does it to Ella and the other women.
Piers then finds a girl who doesn't slap him and changes his mind about women. George then puts everyone back to normal.
Meanwhile, Casey gets a job as directory enquiries and the speaking clock to save up for a doll's house.
Janet's mother Ella becomes a trainee JP. When visiting Janet and George she comments on the fact that Ollie hasn't spoken a single word yet. He responds by talking a language that sounds like baby talk (George has been teaching Ollie the language of Jupiter). With Ella's thoughts in mind, George goes out to get some educational stuff for the kids, he ends up getting porn for them and giving Ollie a cigar and alcohol. Ella takes Ollie and Cassie away from Janet and George but without them Cassie reverts to being a normal human.
Thermoman liberates the stolen Mona Lisa from an art thief's clutches, but comes under suspicion from Scotland Yard when he cannot explain its presence in his flat.
George and Arnie discover a way to filter out prejudices in peoples' brains. This sounds like a good idea until the brains get muddled up
George starts doubting his invincibility, and starts disapperaing.
As an attempt to get Ollie to eat his vegetables, George gets Ultroneon GM vegetables, with unfortunate side-effects. He then makes the minke whale extinct by using it to plug a volcano! Piers decides that Thermoman has gone too far, and makes a campaign against Thermoman abusing nature, thus getting him a TV show. George's attempts to be environmentally friendly backfire until he gets so angry that he has a temper tantrum and moves the Earth away from the sun...
Meanwhile, Mrs. Raven tries to get the Triplets into a Christian School...and has to rely on Ella, who has recently eaten the Ultronean GM fruit!
George's family discover the joys of reality TV.