This piece originally appeared on iHorror.com.

A pretty, sandy-haired young woman is stalked by a mysterious figure; first via car, then by creepy phone calls, and then directly outside her window. He’s even seen in the background spying on her while she converses on the phone. She eventually takes the shadowy figure head-on, stumbling around a living room and fighting for her life, ending with a climax that reveals nothing about the madman’s motivations. Oh, and the whole thing was directed by John Carpenter in the late ’70s. Gotta be Halloween, right? Wrong.

Though it wrapped shooting two weeks before Halloween even went into production, John Carpenter’s television directorial debut, the NBC-produced Someone’s Watching Me! was actually released one month after Halloween. Due to this loopy timeline it’s easy to think Halloween informed many stylistic choices of Someone’s Watching Me!, when in reality it’s the other way around.

Leigh (Lauren Hutton) is an ambitious television producer who moves from New York to Los Angeles. She settles in a large high rise apartment, the kind where the living room is basically one giant window overlooking the thoroughfare. Unbeknownst to Leigh, a creeper who lives in a building across the street spots her and takes a real liking to her. He starts following her, calling her, and leaving her gifts. She continually rebuffs the mystery man, causing him to pursue her more aggressively. With the support of her co-worker Sophie (Adrienne Barbeau) and her boyfriend Paul (David Birney), Leigh goes to the police. Tired of the cat and mouse game, the creep finally attacks.

While not an exact Halloween clone, Carpenter admits SWM! did lay the groundwork for what would become his slasher masterpiece. “A lot of the shots, the framing – and a lot of the flow”, would be reused for Halloween. Carpenter also says, “I got to make mistakes”, referring to the TV movie, which allowed him to hone and sharpen the basic idea and deliver a much leaner and ultimately more frightening movie with Halloween. There are a few familiar Carpenter players in the small cast, namely Adrienne Barbeau and Charles Cyphers. And if you pay attention, you’ll probably spot some names in SWM! that Carpenter would later reuse, including Leigh, Paul, and Officer Tramer.

Noticeably absent from SWM! are a few trademarks Carpenter’s films would come to be known for. He had no input on the score, so here his usual piercing synths are substituted with dramatic, swelling strings – common in ’70s television productions. And his stunning wide-angle lens shots – usually courtesy of Dean Cundey but here provided by Robert Hauser – have been cropped and tightened to fit the 4:3 aspect ratio of a TV screen. Still, the movie displays all the great themes the director would come to be known for, including voyeurism and paranoia.

Watching SWM!, it’s clear that Carpenter who, in 1977, was still new to the horror genre (at that point he only had two feature films under his belt: the sci-fi satire Dark Star, and Assault on Precinct 13, a dystopian Western exploitation flick), was heavily inspired by the works of Alfred Hitchcock – mainly, South By Southwest, Rear Window, and Psycho. At times it feels like it could be entitled Alfred Hitchcock’s Halloween, and I mean that in the best way possible. For a TV movie made in the ’70s, SWM! is incredibly suspenseful and flat-out spooky. The tension builds, keeping you guessing until the very end.

Someone’s Watching Me! is often called “the lost Carpenter film” due to its relative scarcity on home media, but don’t let the hoity-toity label exclude you – I assure you it’s not just for the John Carpenter completest. In fact, I would consider it required Carpenter, especially if you’re a fan of Halloween. It’s one of those special movies that shows its director in transition; especially powerful here since Carpenter’s next film would prove to be his greatest success.