Culture Shock: Are cliffhangers dead? Find out next week . . .

It is the most successful podcast in the world, but its maker admits the title may cause confusion. "We didn't conceive of it as a crime show," says Sarah Koenig, the producer and presenter of Serial. "It's a mishap of the name." But the show, a true-crime story about the death of a teenage girl and the man imprisoned for her murder, told in weekly instalments, has invited that reading. Lately, it may have got out of hand.

The podcast, a spin-off from the popular US radio show This American Life, has doggedly retraced the events leading up to the murder of Hae Min Lee and the ensuing unsatisfying trial, in Baltimore, from 15 years ago. Koenig speaks to witnesses, to relatives, to detectives, to legal professionals and, most frequently, to Adnan Syed, Lee's ex-boyfriend and the man convicted of her murder, a charming, well-spoken figure who has always insisted that he's innocent. "I'm not a detective, or a private investigator, or even a crime reporter," Koenig said at the start of the first episode. But her audience seems to be behaving like one.

On diligent recap sites, listeners review the evidence, compare notes, cast doubts, speculate and theorise. Some have been reprimanded for posting personal details of people involved in the case. We are somewhere between an overinvested audience and the worst jury ever.

Yet for all Koenig’s disclaimers – her purpose is to tell the whole story, not to exonerate Syed – there are inevitable encouragements to engage with it as if it were genre fiction, particularly the cliffhanger endings to each episode.

Koenig's sign-offs anticipate what's still to come. "They're on the lookout for another explanation entirely," she says of a legal team. "Me, I'm going to stay right here at home, with my little garden spade, scraping at the thing that confuses me most: Jay. Next time on Serial . . ."

Koenig may not be a detective, but she is a consummate storyteller, and storytellers have long known that the cliffhanger is the surest way of hooking an audience.

It's hard to find any history of serials, and the cliffhanger device, that doesn't begin with Scheherazade, the narrator of One Thousand and One Nights. The betrayed and embittered Persian king Shahryar marries a procession of virgins, executing each one the next morning, until he marries Scheherazade, who, on the night of their wedding, begins a story that she does not conclude. Night after night she ends one story by trailing another, and the king, forever curious about the fate of Aladdin, Ali Baba or Sinbad, postpones her execution every time. A thousand and one nights later the king has fallen in love with her; a capacity for serial storytelling has ensured her survival. It may be the most supremely artificial device of spun-out fiction – tune in next time to find out! – but the cliffhanger began as a matter of life and death.

When Victorian fiction writers had their work published by instalments, they knew the benefits of leaving readers hanging. Riots broke out in 1841 in New York among Charles Dickens fans waiting to learn the fate of Little Nell, in The Old Curiosity Shop, and the following year in Paris among readers who couldn't afford to buy the conclusion of Eugène Sue's The Mysteries of Paris. Alive to the hokeyness of the serial form, the author Wilkie Collins said, "Make 'em cry, make 'em laugh, make 'em wait."

It shouldn't be surprising to see the rise and fall of shock and suspense in every popular medium. The damsel in distress tied to the railway tracks, and cowboys deserted on the cusp of a shootout, were staples of silent-movie serials – and a marketing ploy. "The cliffhanger, as such, is gone," pined William C Cline in his loving and terribly titled Serials-ly Speaking: Essays on Cliffhangers. "When television has toyed with the cliffhanger technique, it has usually treated it tongue-in-cheek or with outright cynicism." You could put that point to JR, in Dallas, or Dale Cooper, in Twin Peaks, who ended the show on a cliffhanger 23 years ago and – who knows? – may finally resolve it with a new series. But not to Nidge, in Love/Hate, who politely confirmed his death with a press release.

Today, well versed in tropes and painfully self-aware, we tend to find cliffhangers hackneyed or terribly meta, an invitation to stay up too late watching Netflix, or the guiding logic of internet click bait: “27 reasons cats are taking over the world (the eighth will astound you)”. But cliffhangers were always supposed to be infuriating. They rudely assert the hand of the maker, rupturing the spell of a story with a commercial proposition – put a coin in the meter or tune in next week – and manufacture a desire to know more.

Serial is widely vaunted for exploiting the newest medium, the podcast, for long-form storytelling, and it may be the most compelling story currently on any medium. But it's using the oldest trick in the book. Now that it has entered its final act, the show's more ardent fans may perceive a rift between the temptation of its structure and the story it can deliver. If a real case doesn't yield the shocks and twists of a fictional narrative, what happens then? That counts as a nail-biting cliffhanger. pcrawley@irishtimes.com