John Carpenter’s 1982 summer gross-out flick The Thing didn’t invent the modern sci-fi horror genre. That honor goes to Ridley Scott’s seminal Alien, released three years earlier. The science-fiction-horror hybrid is as old as science fiction itself — Mary Shelley’s Frankenstein from 1818 could be considered the genre’s first iteration. But Alien took advantage of a new aesthetic of ’70s-era cinematic realism, along with a budding revolution in special effects, to reimagine the golden age sci-fi horror movies of the 1950s — those hammy classics about creatures from outer space and allegories about nuclear-age catastrophes. Cold War paranoia gave cinema immortal monster movies such as Godzilla, Invasion of the Body Snatchers, the giant-ant creep-fest Them! and Howard Hawks’ original The Thing from Another World.

With its giant bug-monster, its human-incubating fetus, and its phobia of technology, Alien channels all the 1950s tropes. Its perfect balance of sci-fi and horror elements make it one of the classics of the genre, no doubt. But let’s face it, it takes forever to get going. The last hour is pure terror, but there is a lot of build-up. The Thing, meanwhile, does everything that Alien does — both movies are versions of Agatha Christie’s mystery novel And Then There Were None — and it also hits the ground running, starting with a grabber of an opening scene and keeping viewers on the edge of their seats until the final frame. Below we offer more reasons why John Carpenter’s The Thing is the best sci-fi horror movie of all time.