You need to watch the most heart-pounding sci-fi thriller on HBO Max ASAP

It’s hard to talk about cautionary science fiction without bringing up Black Mirror.

The anthology series has garnered a dedicated fanbase over the years by telling stories about technology, how it aids and maims humanity, and how everything can get so much worse. But for all of Black Mirror’s high points, there’s still one film that better captures both the danger of technology and the disconnect that can happen — as we’ve all seen — when everything becomes connected.

The film is Pulse, an ambitious 2001 sci-fi horror flick that asks the question: What if humans weren’t the only ones who wanted to use the internet to connect? What if ghosts did too?

Written and directed by Japanese filmmaker Kiyoshi Kurosawa, it’s one of the most haunting films of the 2000s, powerful and chilling enough to make you wish you had never spent a second looking at a computer screen. And it’s streaming now on HBO Max.

Here’s why Inverse recommends that you watch it ASAP.

“Would you like to meet a ghost?” That’s the message Ryosuke Kawashima (Haruhiko Kato) sees after connecting his computer to an Internet Service Provider for the first time. Moments later, the message disappears and is replaced by a video of a man sitting in an apartment with a garbage bag over his head and crazed scribblings painted on the wall behind him. It looks like a murder scene. Ryosuke understandably shuts the computer off.

But turning off the computer isn’t enough to stop what’s happening in Pulse, as Ryosuke and the rest of the film’s characters soon learn. The things trying to communicate and seep into civilization via humanity’s digital screens are simply too persistent, too desperate to rediscover connection, or at the very least, share their disconnection with others.

So the world becomes populated by black stains on walls where people used to be, and rooms sealed off with red tape, holding untold terrors within. At first, both things seem like nothing more than rare oddities, but when Kurosawa broadens his scope in the film’s second half, you realize just how out of control everything has become.

The film’s uneven but admirable third act follows two of the film’s characters as they dare to stay together in a world that seems to have erased the very concept of that connection.

Nothing about Pulse would work if it wasn’t executed with the same level of patience and control that Kurosawa brings to it. One of the most gifted filmmakers of his generation, Kurosawa shoots his actors in empty rooms and under lifeless, smog-filled skies, highlighting the ugliness of the world and the negative space that surrounds the people in it.

The filmmaker keeps his frames relatively simple and his cuts minimal. He lets you find the terror lurking in the backgrounds, corners, and shadows of his images — encouraging your participation while filling with you dread. The moments when the horrors of Pulse step out of the shadows and into the light — as one literally does in the film’s most terrifying sequence — are some of the scariest you’ll ever see on-screen.

But of all of the quietly disturbing images that Kurosawa fills Pulse with, perhaps few linger as long as the grainy shots he shows of strangers simply pacing and sleeping in their apartments, dying inside while their devices silently watch them expire.

Pulse is streaming now on HBO Max.