The recurring English comic characters Charters and Caldicott also appeared in the film.
Susan Graham (Carol Marsh) is a discontented heiress whose joint guardians (Mervyn Johns and Peter Haddon) are both trying to get her married to their odious nephews (Peter Hammond and Geoffrey Sumner, respectively). On her nineteenth birthday, the five of them visit a nightclub called the Magnolia Club; also present happens to be radio star Nick Martin (David Tomlinson), whom Susan detests. When she is inadvertently seated at Martin's table directly in front of the floor show, she refuses to move, and Martin, despite his radio reputation as a fearless detective, is too intimidated by her hauteur to insist. This, however, proves to be a mixed blessing for Susan; when the evening's principal performer, a ventriloquist, comes out, she laughs so hard at his routine that she gets a bad case of the hiccups. She attempts to cure them by getting a drink of water, but succeeds only in getting caught in the crossfire of a pie fight.
Four days later, Susan's hiccups still haven’t stopped, and her doctor (Wilfrid Hyde-White) recommends that her guardians take her to a certain haunted house for a good fright. On the way, they stop at a pub for directions, and Susan runs into Nick Martin again. At first, she is still chilly towards him, but then the narrator (Richard Hearne) shoots the two of them with Cupid's arrow, and they immediately fall in love. Martin's overbearing mother (Judith Furse), however, soon comes to take him away – but not before the two of them have arranged a rendezvous.
The plot then proceeds to the haunted house, where Susan's guardians, not believing in the ghost, have hired an actor to play the part. Susan, however, slips away to her rendezvous before he begins working; consequently, she still has the hiccups when Mrs Martin finds her and Nick trysting together. This fact doesn’t amuse Mrs Martin, who apparently believes that hiccups are contagious; she forbids Susan to see her son again, and suggests that she see a psychiatrist (Jimmy Edwards) about her problem.
The psychiatrist concludes that, because Susan got the hiccups from laughing, she can rid herself of them if she laughs that hard again. He recommends “a fellow on a BBC show called Jimmy Edwards”; Susan accordingly goes to the BBC studios, where, naturally enough, she meets Nick again. The two of them arrange a date at the Magnolia Club, ostensibly so Susan can cure her hiccups by laughing at the ventriloquist again, but really so they can gaze into each other's eyes all night. Their reverie is interrupted, however, by Mrs Martin, who shows up at the club and orders her son home. When Nick fails to stand up to her, Susan, disgusted, storms out of the club, inspiring Nick, a little too late, to develop a backbone and tell his mother off.
Returning home, Susan writes a letter to Nick breaking off their relationship, but the Martin address turns out to be unlisted. She therefore returns to the BBC and leaves the letter on his microphone; on her way back out, however, she mistakes the door and ends up locking herself in a supply closet. The next morning, she turns up missing; Nick, frantic, sets all of England looking for her, and at first refuses to broadcast until she's found. Being persuaded, however, that his program is necessary for the social stability of the nation, he returns to the BBC that evening; in the course of the broadcast, the closet door is opened, and Susan tumbles out, unconscious. She is, however, quickly revived – and, what is more, when she sees her guardians’ nephews (who have inadvertently locked themselves into, and then flooded, the mixing room), she bursts out laughing, thereby finally curing herself of the hiccups. She and Nick fall into each other's arms, and all ends happily.
Helter Skelter is as much a variety program as it is a narrative film; it includes numerous scenes that have only the faintest connection with the plot, and are included principally for their stand-alone comedy value. The following are noteworthy:The ventriloquist routine that gives Susan the hiccups is shown in full; it features Robert Lamouret and a Donald Duck puppet.
While Susan is being shown her bedroom at the haunted house, the maid (Patricia Raine) has a fantasy in which she becomes a notorious 17th-century courtesan, the romantic interest of both Oliver Cromwell (Bill Fraser) and King Charles II (Jon Pertwee).
In a vain attempt to make Susan laugh, the psychiatrist shows her one of Jimmy Edwards's silent-comedy sketches, involving four spies trying to seize an inventor's briefcase.
During Susan's first trip to the BBC, Terry-Thomas is shown as a frantic disc jockey whose assistant has broken the record he was supposed to play; in desperation, he attempts to sing the song himself, despite sounding nothing like the original recording artist. (This would later become a staple routine of Thomas's, known as the "Technical Hitch" sketch.)
Director Ralph Thomas called the film "one of those 'Friday night pictures'" he made under Sydney Box. "You were quite likely to finish shooting on Friday, plan to go into the cutting rooms on Monday to look over your stuff and get your cut ready, then go for a drink, and you'd be given another script and be told, 'The sets are standing and you start on Monday - this is the cast!' It wasn't necessarily good and we didn't get a lot of money, but it was regular."
Thomas did not "particularly want to make comedies, but I said I'd enormously admired a crazy American picture called Hellzapoppin! We cast it well and enjoyed making it, although I never quite understood the storyline. Funnily enough it has become a sort of cult picture in odd places."