April 26, dubbed #AlienDay by Fox, sees a one-night-only re-release of both the oldest and the most recent installments in the Alien franchise: Alien and Prometheus. That these films are so different in tone speak to how many things the franchise has become since Alien’s release nearly 40 years ago: an action series, an epic space opera, a deep study in dystopian science fiction, and a staunchly feminist pro-choice narrative. But what it hasn’t really been, at least not since Ridley Scott’s 1979 classic original film, is full-on horror.

The new trailer for Alien: Covenant, Scott’s follow-up sequel to Prometheus (and thus still a prequel to the rest of the franchise) seems to indicate that might be changing.

How do we know? Well, for starters, it is scary, and it gives you plenty of images of Katherine Waterston as a heroine who obviously mirrors Sigourney Weaver’s legendary character Ripley. And the plot, which follows bunch of unwary colonists arriving on a planet and discovering they’re being hunted by the Xenomorphs (the adult aliens), is highly similar to Alien.

The trailer for Alien: Covenant is also structured and edited like a horror trailer. Even more tellingly, it’s structured and edited like the original Alien trailer.

If you’ve never seen the original trailer for Alien, or if you haven’t seen it in a while, take a moment, turn up the volume, and immerse yourself in it.

Spoiler — it’s scary as hell.

The Alien trailer is a perennial entry on lists of the scariest trailers ever, and helped establish a template for how to edit an impactful horror trailer. You can see its influence in countless horror trailers today, to the point where its beats have practically become horror clichés in their own right.

Let’s break down the ingredients.

The original Alien trailer’s structure mimics the structure of a horror movie

Pacing is one of the most important elements of good horror. The vast majority of horror movies follow a very basic pattern: a buildup of suspense and a release of tension, loosely structured as a slow build and exposition in the first third, rapid plot expansion in the second, and a cathartic release in the final third.

That’s also the approach the original Alien trailer takes. The first full minute of the two-minute trailer is pure buildup, in the form of increasingly dread-inducing close-ups of the now-famous alien egg, with that famous Pong-bar font slowly forming overhead. When the egg finally cracks, 56 seconds in, the trailer switches to actual shots from the movie. Here, the editing cuts back and forth between sequences of the crew of the Nostromo exploring the strange alien world they’ve found, Jonesy the cat looking creepy, and Ripley and the crew obviously being hunted by something unseen.

Finally, at 1:39, violence erupts, and the next 11 seconds are a rapid, explosive burst of scary things happening beneath a continual eruption of sound, until at 1:50 everything goes quiet for the movie’s famous tagline (“In space, no one can hear you scream”) and title card.

All of this is accomplished without any dialogue whatsoever.

Alien: Covenant’s trailer, meanwhile, utilizes dialogue, but the structure is essentially the same. The first 57 seconds of the trailer are exposition about colonists arriving to a new planet — one that seems to be the planet we glimpsed briefly at the end of Prometheus. The scene gradually shifts into the colonists realizing that something much darker is going on. At 57 seconds, the first title card appears. From there through 1:37, the editing shifts to more explicitly scary scenes intercut with a tagline (“The path to Paradise begins in Hell”). And then at 1:38, all hell breaks loose.

Repetitive sound is a crucial tension-building element

At 56 seconds in the Alien trailer, the alien egg cracks, and simultaneously, a kind of shrill wail begins. (Is it an emergency alert? A terrifying alien call? It’s a spine-tingling noise, whatever it is.) One of the most terrifying things about the Alien trailer is that that noise just won’t stop coming for you.

This sonic repetition has become a staple of trailers these days, appearing in many forms, from the famous Inception Brmmmmm! sound to the more recent trend of the single creepy piano note. The type of sound isn’t as important as the fact that it keeps happening and you can’t make it stop.

And wouldn’t you know, Alien: Covenant uses this tactic, too, in precisely the same place as Alien’s trailer, only the recurring theme is a creepy choral hum over a synthesized clap. If you listen closely, you can hear faint echoes of the original Alien wail in the final third as well.

These trailer tropes are everywhere

You can see the influence of the original Alien trailer all over recent horror. Take, for instance, the recent trailer for Life, which is somehow not a part of the Alien franchise yet seems to be borrowing plenty of its beats.

The structure isn’t limited to movies about aliens, either. A24’s upcoming horror film It Comes At Night recently released a fantastic trailer that adheres to this basic structure almost perfectly: a steady buildup followed by rapid plot expansion, followed by a few final seconds of sheer chaos, all beneath a strategically placed repetitive sound.

Within the Alien franchise, it’s not just Alien: Covenant that uses all these tricks from the original trailer. Prometheus did it, too. In fact, the Prometheus trailer is even more like the original Alien trailer.

Prometheus’s trailer is a reminder that it’s not wise to try to gauge the level of horror that Alien: Covenant might bring to the franchise based on the trailer alone. While Prometheus did have one famously visceral horror sequence, it was more a cerebral tone poem that belonged very much to the realm of sci-fi.

But this hasn’t stopped horror fans and Alien lovers from praising Alien: Covenant as a marked improvement over Prometheus.

You versus the guy she tells you not to worry about pic.twitter.com/Ui8IFDKQS4 — Tony Kelly (@tonykellywriter) March 1, 2017

It’s too early to determine whether this type of assessment is true, but it’s probably telling that the marketing team of Alien: Covenant has given us so many early images of the Xenomorphs in the film. Spoiling their appearances up front is a reassurance to the series’ legions of fans that, yes, there will be actual aliens in this alien movie.

The trailer also serves as an additional form of reassurance that the franchise is hopefully returning to what it does best: sending a bunch of people with guns into uncharted territory to fend off terrifying monster attacks.