When Lucy enters a TV Quiz Show, Old Tom helps her study. However, Billy is one of the other contestants and, on the day of the show, he tricks Lucy into catching the wrong bus. When Lucy doesn't turn up at the TV studio, Old Tom - who is in the audience with Angela - rushes onto the set and takes Lucy's place in the quiz. Because he helped Lucy study, Old Tom knows most of the answers. However, Billy is cheating and nearly wins, until Old Tom accidentally drenches him and washes off all Billy's cheat notes. On the last question, Billy can't cheat any more, but Old Tom gets the answer right…and wins the contest.

Angela and Old Tom go to the local swimming pool, where they meet Lucy who is practising for her swimming certificate. Billy is also there and starts showing off. However, he goes too far and is kicked out of the pool by the lifeguard. Angry and jealous, Billy tries to sabotage Lucy's attempt at her swimming certificate by turning on the pool's wave machine. However, he accidentally breaks the machine, knocks out the lifeguard, and ends up in the pool himself. Old Tom saves them both by ingeniously pulling out the plug and draining the pool.

Angela and Old Tom go to the beach, where Old Tom gets involved in a sandcastle competition. While waiting for his sandcastle to be judged, Old Tom goes swimming and meets a baby whale, and plays with him underwater. Meanwhile, on shore, Billy pretends Old Tom's sandcastle is his own, so he can win the competition. With the judging about to begin, Old Tom races back to shore, but accidentally smashes his own sandcastle. However, with the help of the whale, he ends up winning the competition, after all.

Angela buys Old Tom a novelty radio, shaped like an apple. However, Old Tom, thinking it is an apple - eats it! All of a sudden, strange voices start coming from Old Tom. Angela thinks Old Tom can talk, until a doctor diagnoses the problem and offers to remove the radio. However, Angela can't afford the operation, so Old Tom tries to raise money by entering a singing competition, using the radio as his 'voice'. The deception is discovered and Old Tom is thrown out, so Angela goes to a bank to apply for a loan. Suddenly two bank robbers enter, but a broadcast from Old Tom's radio makes them think they are under arrest, and they give up. The police chief arrives and pats Old Tom on the back, dislodging the radio. With the reward money, Old Tom buys a new radio.

Old Tom wants to play with Lucy but is not allowed to, because she has chicken pox. Old Tom goes home and paints spots on his face, so Angela will think he has chicken pox, too. However, instead of letting him play with Lucy, Angela insists that Old Tom stay in bed. He manages to sneak off, but when he gets to Lucy's place, his spots are accidentally wiped off. He races back home and starts to paint them back on, but Angela catches him. She washes them, but they don't all come off - Old Tom really has chicken pox, after all!

Angela and Old Tom are planning to go to the zoo, but the car breaks down. As Angela tries to fix it, Old Tom is accidentally picked up by a garbage truck and deposited at the zoo. There he has adventures in a lion's cage, has tea with the chimps and escapes from two attendants. When he hides in a rubbish bin, he is picked up by a garbage truck again and deposited back home. Angela hasn't noticed he was missing and, now the car is fixed, they drive off to the zoo. To Angela's surprise, all the animals seem to treat Old Tom like an old friend.

Lavinia decides to 'elevate the cultural tone' of Angela's household, by giving them regular musical recitals on her violin. Her talent, however, is negligible, and Old Tom and Lucy can't stand the racket. When Lavinia and Angela go out for a cup of tea, Old Tom has a go on the violin and discovers he is a prodigy, fiddling a tune so fast that he breaks all the strings. Lavinia returns, but doesn't notice the broken strings because she is in a hurry to get to a TV talent show, on which she is a contestant. Lucy and Old Tom hope Lavinia wins because the first prize is a trip around the world - which means no violin recitals for six months! However, they realise she can't win, because her violin has no strings. So Old Tom, grabbing another violin, races off to give Lavinia a helping hand.

Angela tries to get her old car repaired, but is talked into trading it in for a new car, instead. The salesman persuades Angela and Old Tom to test drive a sports car, but Angela drives so timidly that Old Tom floors the accelerator. The car zooms through town, attracting the attention of a traffic policeman who gives Angela a ticket. Angela returns the sports car and next tries a four-wheel-drive. But that is too powerful, so she tries a limousine which is so sophisticated she can't even drive it. Eventually, Angela decides to keep her old car, but learns it has been taken to the wrecker's yard. So Old Tom has to race off and save it.

Lavinia comes to take Angela golfing. Old Tom and Lucy want to go golfing, too, but Lavinia tells them the golf club won't let 'undesirables' play - they have to stay home. At the golf course, Angela is excited because, even though she has never played golf before, she turns out to be a natural, and easily out-plays Lavinia. This infuriates Lavinia, who starts to cheat. Meanwhile, Old Tom and Lucy, sneak onto the golf course and spy on Angela and Lavinia - noticing that Lavinia is cheating. They secretly undo Lavinia's cheating, so that Angela wins the game. The club manager is so impressed with Angela's skill that he offers her life membership. But when he tries to chase off Lucy and Old Tom for being 'undesirables', Angela refuses, saying she'd rather be with her friends.

Old Tom is being pestered by a bird which has built its nest on top of Angela's chimney. The bird disturbs Old Tom's sleep, takes his food and fills the house with smoke. Old Tom is just about to squirt it off with a hose, when a bulldozer arrives. The driver explains he has come to knock down Angela's house, to make way for a freeway. He says Angela and Old Tom will be re-housed in a modern apartment block. They check out the apartment - but it's hideous, and they decide to stay in their home. As the driver starts his bulldozer, Angela, Lucy and Old Tom hold a tea party in front of it, blocking its way. Just then, the bird flies down to take Old Tom's food, and the driver recognises it as a rare species. Because it's nesting on the house, he can't knock it down after all.

Lavinia persuades Angela to buy Old Tom a computer, so he won't get up to mischief. When the computer arrives, Old Tom is more interested in playing with the box, so Angela tries the computer instead. She is hooked immediately, surfing the internet and paying no attention to Old Tom or anything else. He takes advantage of this by getting up to mischief - preparing his own food, and kicking a football inside the house. But the fun soon palls for Old Tom - the place is a mess, he runs out of food, and he misses Angela. In desperation, he enlists the help of Lavinia and Lucy, who realise Angela is hypnotised by the computer. They rush her to the nearest café and give her a cup of tea. Soon, Angela is herself again - until she discovers it's an internet café!

While Angela is sleeping, a couple of thieves sneak into her house and steal her most treasured possession - a valuable antique vacuum cleaner. Old Tom, however, sees them and hides in the back of their getaway truck, leaving a trail of sweetie wrappers behind him. When the thieves unload the stolen goods into their warehouse, they unknowingly unload Old Tom, too. Meanwhile, Angela wakes up and discovers that her vacuum cleaner - and Old Tom - are missing. With a policeman's help, she follows the trail to the warehouse, where Old Tom catches the thieves and hands them over to the policeman.

Old Tom overhears Lucy and Angela complaining about Billy, and mistakenly thinks they are talking about him. Devastated that not even his best friends really like him, Old Tom runs away from home and joins a circus. There, he is immediately accepted and told that he is not the 'no-hoper' he thinks he is. With the encouragement of the Ringmaster, Old Tom learns that everybody has a talent, and his talent is to make people laugh. Meanwhile, Lucy and Angela search the town for Old Tom and eventually find him in the circus - just as he is doing his act. They clear up the misunderstanding with Old Tom, telling him they were always proud of him and always will be, and he returns home with renewed faith in himself.

When Old Tom is finishing his bath, his favourite bath toy - a rubber duckie - goes down the plug hole and gets stuck in the house's plumbing. Old Tom tries to retrieve the toy, but ends up soaking Lavinia, who has come for tea. On Lavinia's advice, Angela calls a plumber who, with Old Tom's help, tries to fix the problem. But he, too, accidentally soaks Lavinia. Tired of all the drenching, Lavinia leaves, only to be soaked again when the blocked garden hose explodes, flooding the house - but finally releasing the little rubber duckie.