IT Chapter Two, the follow up to the 2017 hit, has arrived in theatres with fangs bared, and it’s at times shocking, sentimental and long.

So very, very long.

Granted, at 1376 pages the Stephen King novel on which it is based is no pamphlet. But neither are most of King’s books. They tend to be long on domestic details and short on plot.

On sheer volume alone King’s novels must be relatively straightforward to adapt to the screen as I can’t imagine there are too many writers outside Agatha Christie who have had a more extensive library of their works filmed.

In the hands of a first-rate director like Stanley Kubrick or a slickly exploitative director like Brian De Palma, King’s books provide splendid source material.

These directors know how to separate the wheat from the chaff in King’s work – that is, what to leave behind. But IT and IT Chapter Two director Andy Muschietti is no Stanley Kubrick.

After an arrestingly brutal prologue, IT Chapter 2 kicks off 27 years after IT concluded.

Mike (Isaiah Mustafa), the sole member of the Losers Club who has remained in the troubled town of Derry, Maine, summons his childhood pals Bill (James McAvoy), Beverly (Jessica Chastain), Richie (Bill Hader), Ben (Jay Ryan), Eddie (James Ransone) and Stanley (Andy Bean) homeward to confront once again the homicidal clown Pennywise (Bill Skarsgard).

These establishing scenes are easily the film’s most satisfying as we are introduced to the club as adults, and witness how that terrifying summer back in 1989 poisoned their lives.

Once the Losers (minus Stanley) gather in Derry’s Chinese restaurant, the tension is handled adroitly as Pennywise fires the first shot in their impending showdown.

Sadly, from there it’s mostly downhill.

For a tome of its size, IT the novel is quite light on plot.

Distilled to the cinema is becomes clear that what plot there is in Chapter Two is essentially a 2-hour 49-minute episode of Scooby Doo Where Are You? (if one replaces the Ghost Clown or the Creeper with a three-metre naked demon lady with a set of fangs in her throat).

First, the gang establishes there’s a monster afoot terrorising the community. Next, they split up, with each segment of the split encountering the monster and narrowly escaping.

Then the gang find themselves in a creepy chamber, where scary things jump out at them and there is much running through and slamming of doors. Finally, the monster is unmasked as an imposter, something much less terrifying than first suspected.

It’s the second Act, where the individual members of the club confront and survive Pennywise, that’s the killer.

These encounters go on endlessly and each successive scare lessens the impact of the next.

Muschietti seems awake to these dangers, attempting to use Pennywise as a kind of defibrillator, bringing sagging narratives to life with an electric jolt.

But that approach can’t work indefinitely: Eventually the audience will be saying to itself, ‘Ha! That poster/statue/murdered little brother (whatever) is about to transform into a fanged clown and go postal’.

We can always see where the next attack is coming from, which makes it all the more frustrating that the Losers can’t.

Of the Losers, Hader’s Richie probably comes off the best, mostly because as a neurotic stand-up comic he gets all the best lines.

James Ransone, Jay Ryan, Isaiah Mustafa, James McAvoy, Jessica Chastain and Bill Hader toast each other in IT Chapter Two. Photo: New Line Cinema

Skarsgard’s Pennywise is disturbing enough early on, but we see him so often familiarity breeds contempt.

He may invade everyone’s dreams initially as terrifying childhood memories given form, but he concludes as little more than the creepy, loud-mouthed uncle you have to tolerate every Christmas who is quickly forgotten for the rest of the year.

The conclusion to King’s novel is pretty much unfilmable and Muschietti appears to make the same mistake as the 1990 miniseries in mistaking pyrotechnics and noise for resolution.

It’s a shame, because there is a better film to be made from the source material.

But a movie that insists on making references that draw attention to superior King adaptations like The Shining and Stand By Me really sets itself up for failure.

Critical failure that is: I’m sure IT Chapter Two will be an enormous hit. But that’s another horror story.