WRITER-DIRECTOR Stephen Susco's belated sequel to the 2014 horror thriller Unfriended retains the neat stylistic conceit of piecing together a fractured narrative in windows that appear on a central character's laptop screen.

Music and video streams overlap with typed conversations on social media channels as the protagonist accesses a browser to search for clues to a chilling mystery.

The hapless hero's face, etched increasingly with fear, is visible in one of the windows, creating the illusion of events unfolding in real time.

Like its predecessor, Unfriended: Dark Web retains a waft of suspense for the opening 15 minutes but this dissipates as the script loosens its grasp on plausibility to deliver explosions of sickening violence and a risible final twist.

The sequel also flouts its own rules.

A shadowy villain explains that a girl will be murdered if the characters - linked via video conferencing - alert the police or move out of the field of vision of their cameras.

Almost immediately, one protagonist disappears from their video stream for an extended period.

There is no punishment for this infraction, erasing jeopardy that should be hard-wired into every flickering frame.

Matias O'Brien (Colin Woodell) acquires a replacement laptop to develop a sign language application to communicate more effectively with his deaf girlfriend, Amaya (Stephanie Nogueras).

The machine crashes twice and Matias seeks help online from technical wizard Damon (Andrew Leeds), who is based in London, and a coterie of pals comprising AJ (Connor Del Rio), Lexx (Savira Windyani), Nari (Betty Gabriel) and her girlfriend Serena (Rebecca Rittenhouse).

In the process of cleaning the computer's overloaded hard drive, Matias uncovers hidden files, which provide secure access to a chatroom called The River.

AJ, Damon and co are party to Matias's progress thanks to screen sharing and they witness his journey into the dark web.

The pals urge Matias to exit The River but the real owner of the laptop, a shadowy figure named Charon IV, makes contact.

He threatens to kill Amaya unless the machine is returned immediately.

Matias and his terrified pals become embroiled in a frantic race against time to protect Amaya and outwit a mad man, who can hack into any device to remotely hunt his prey.

Unfriended: Dark Web might deliver immersive shudders and jolts when viewed on a laptop or computer but projected onto a big screen, Susco's sequel seldom chills and doesn't thrill.

The plot feels contrived and second-hand, and stylistic conceits prevent us from getting to know Matias and co sufficiently to invest emotionally in their survival.

Media-savvy characters are laughably clueless about the perils of online communication and repeatedly put themselves in harm's way for no other reason than they are destined to perish to meet the obligatory body count.