PARIS — Some French television viewers were likely surprised last month when they switched on one evening to see ... a black screen. At least at the outset. Then, short subtitles begin to appear along with some vague, undulating and colorful forms. Finally, the sound of voices, which turn out to be those of four divers exploring the depths of the Atlantic, in 2026.

A lucky tip has allowed the divers — Gabrielle, Théo, Sun and Isaïe — to find a mysterious cave that contains a strange creature. That's when things start to go wrong ... For 10 minutes, the viewer listens, following the divers' exchanges, which are interrupted by bubbles from their breathing. The background music is simple but engaging, and generates just the right level of suspense as the neoprene-clad protagonists try to escape the beast. "What was that?" A long, watery wail ensues ... "A scream ..."

Hear it all happen, instead of watching. That is the big idea in CALLS, a new series on Canal+. The series premiered on Dec. 15 and consists of 10 episodes to be shown late on Friday evenings on the cable network's scrambled channel.

Better a suggestive sound than a picture that "tells' you what to think.

The choppy sounds in each episode are supposed to be recovered "evidence" of some awful event, one that is now being pieced together as the viewer — or listener really — follows along. Examples include a woman's anxious phone call to the police as someone is trying to break into her home; the black box of a plane that crashed inexplicably into the ocean; even the sound recordings of a film whose crew have all disappeared.

CALLS is 10 "accidental" story chunks that mix elements of the thriller, horror film and science fiction. All, to a greater or lesser degree, conjure Biblical or mythical visions of absolute, Apocalyptic mayhem.

The creator of this surprising series is Timothée Hochet, a young director of online shorts. Hochet was just 23 when, in October 2016, he uploaded his first video to YouTube. The short consisted of youngsters calling one another as they observe, it seems, something paranormal. The impression it left was certainly strange and troubling.

The video soon clocked up 400,000 views and caught the attention of a producer from Studio Bagel, who thought of turning the idea into a series for Canal+. Soon, prominent French actors such as Gaspard Ulliel, Mathieu Kassovitz, Charlotte Le Bon and Kyan Khojandi were lending their voices to the project.

Less is more

The show was born of Hochet's desire to create a truly chilling experience, much like the 911 calls he had heard made to emergency services in the United States. Those sound clips, he explains, made him feel "emotions no film had provoked: fear of the unknown, silence, breathing." Hochet loves horror films but says it's a pity they rely so much on special effects. "The disappointment comes the moment you see the monster," he explains. "For me, the most effective films are those that show less. I like it when a work leaves a big part to the imagination."

In short, better a sparse canvas than a picture with too many details; or in this case, better a suggestive sound than a picture that "tells' you what to think.

François Musy, one of Switzerland's top sound engineers who has worked with famed directors like Xavier Giannoli and Jean-Luc Godard, agrees. Younger generations, he says, are "stuffed with images, all the time." The problem with pictures, Musy explains, is that they leave nothing to the "subjective" mind. "Sound, on the other hand, can deceive," he adds. "And nobody feels it in the same way. One might even perceive it differently depending on the time of the day."

Fear of the unknown, silence, breathing.

While CALLS episodes are typically just 10 minutes long, they are carefully crafted to win and keep the attention of their television listeners. As Musy explains, "Sound must be directed like a crime film and as precisely as any musical partition." In the film Dunkirk, he adds, "Christopher Nolan does not need to show bloody scenes, because he knows how to perfectly dose the moments of silence, and absence."

Back on CALLS: This time we're in a plane cabin during flight; beeping sounds start to mix with scream amid a strangely familiar chaos. Gripping? All you need is your headset and unfettered imagination to find out. I'd say it's certainly worth a try.