Store worker Hal Adden accidentally discovers the genie of the watering can, who will grant his every wish. But when a misunderstanding turns Hal into half a dog, how can he put it right when the watering can gets sold to a new owner?
Hal is due to take his first driving lesson so he can run the store's delivery van. However, an injury sustained playing football means that he can't go for the lesson - at least, until the Genie finds a way to help him out.
Mr. Cobbledick is too upset to enjoy his birthday after the store has been robbed, so Hal gets the Genie to sort out security. Unfortunately, the Genie misunderstands all of his instructions, not least the request to get a boxer.
Hal has now passed his driving test, and has to deliver goods to the local church fete in the company van. While on his way, he decides to spend the time giving the Genie a driving lesson - what could possibly go wrong?
Mr. Cobbledick has agreed to sing in a talent show run by competitive braggadocio Reggie Wadlow. Determined to not let Mr. Cobbledick make a fool of himself, and to teach Reggie a lesson, Hal enlists the help of the Genie.
Hal has to store a doll's house at his flat so it can collected for Mr. Cobbledick's niece. A simple enough task - at least, until the Genie accidentally shrinks Hal to doll-size and places him inside it.
Hal has an easy day to look forward to - with Mr. Cobbledick away on holiday, all he has to do is a simple customer delivery. But whenever the Genie tries to help out, things are never as easy as they seem.
Mr. Cobbledick's domineering sister Henrietta comes for a surprise visit, and quickly makes him a nervous wreck. Hal makes a deal with Patricia - if he can get Henrietta to leave on the 7pm train, she has to go on a date with him.
The opening of a rival hardware store is causing Mr. Cobbledick stress, but counselling sessions don't help - his psychiatrist is undergoing a breakdown of his own.
When Hal needs money to pay for damaged clothes, he and the Genie get some extra work in the clothing store of Mr. Cobbledick's brother. Unfortunately, with the Genie taking everything literally, the only thing they provide is chaos.
The Genie receives a psychic message from another genie called "Ringo", who asks if he can stay for a few days. A young genie from a much more hedonistic background, Ringo is only 700 years old and so has ideas of youthful mischief.
The boastful Reggie Wadlow pressures Mr. Cobbledick to lose weight as part of his keep fit classes. But after Patricia expresses concerns that her dad may harm himself with all the exercise, Hal gets the Genie to help him.
Mr. Cobbledick's sanity has been deteriorating further, and even his psychiatrist has started seeing a psychiatrist. Determined to help him, Hal decides to put his watering can up for sale, and in so doing, get the Genie a new master.