Robert Harmon, director

The screenwriter Eric Red said the idea for The Hitcher came to him when he was driving in the rain and thought of the Doors’ song Riders on the Storm. Specifically the line: “There’s a killer on the road.” John Ryder, the film’s hitchhiking serial killer, was originally described by Eric as having a damaged larynx, meaning he spoke using an electronic voice box. In those early drafts, he was much more monstrous – just a force of evil.

I thought that approach was too simple and wanted to make him more appealing, to suggest there was a heart in there. Ryder is a deliberately ambiguous character – flesh and blood, but with room for a supernatural or mythic reading. While we were making the movie, I’d ask: “If Jim Halsey hadn’t been driving down that particular highway in the rain, would anyone have been standing there?”

Initially I was after Terence Stamp to play the hitcher. He turned the part down but years later I ran into him at a party and he said that, having seen the movie, he wished he’d done it. I think Terence and Rutger Hauer have qualities in common. Their eyes are like jewels – they look like they are not of this Earth. For Jim, I needed someone who seemed ill-equipped to deal with the situation he found himself in, but whose countenance is completely different by the end of the movie. C Thomas Howell was perfect: he’s always seemed younger than his real age.

Rutger came to me with an idea for the scene where Ryder lies on the bed in the dark next to Jennifer Jason Leigh as Nash and she assumes he’s Jim. He said: “I’d like to read poetry to her.” I thought: “How can that possibly work? She’ll know it’s the wrong voice.” But I was a very green director and remembered Rutger’s beautiful “tears in rain” scene from Blade Runner. When we rehearsed the scene, Rutger recited his own godawful poetry and I thought: “This is the end of my career. I’m dead.” He finished, came over and said: “It doesn’t really work, does it?” “You know what?” I said. “I kind of think you’re right.” I felt like the luckiest man in the universe.

I’ve often seen The Hitcher described as a horror movie, but that’s not a genre I’m interested in. The original script was much more violent and had moments I thought went too far. For example, when Jim finds a severed finger in his burger and fries, the script originally called for an eyeball and a note from Ryder saying: “I’ve got my eye on you.” Still, despite the fight put up by HBO all the way through filming and even into post, there was never any question we weren’t going to kill the girl.

C Thomas Howell, played Jim Halsey

So many people have said to me: “Oh my god, I had nightmares over that scene where Jennifer was ripped in half. I can’t believe you shot that!” Well, we didn’t. You see her tied between two trucks and Ryder stepping on the gas and the tyres spinning – but then the scene fades out. The movie encouraged audiences to use their imagination.

It was my second picture with Jennifer and I marvelled at how she committed to the character of Nash. Nash’s relationship with Jim is beautifully innocent, and I’m glad it’s not romantically driven – there may have been a sex scene in an earlier version of the script, but The Hitcher is better for not falling into that cliche.

Rutger seemed to terrify everyone on the production and was pretty much left alone. I think he enjoyed the power he had over people. About three weeks in, he said: “I think we should have lunch together.” I went to his trailer and we sat in dead silence as he chain-smoked filterless Camel cigarettes. After an eternity, I mustered up some courage and in my squeaky teenage voice said: “Rutger, what’s your secret to playing bad guys?” He took a long drag of his cigarette, leaned into my face, slowly exhaled and whispered: “I don’t play bad guys.” I just gathered up my things, thanked him for lunch and backed out of the trailer.

That phrase rattled around in my head for years, until I had enough life experience to understand the importance of injecting humanity into villainous roles. There are moments in The Hitcher where Ryder looks at Jim with utter empathy. He expresses fear, too, the full body of emotions. I didn’t question any of Rutger’s improvisations – whether he was scooping a tear off my cheek with a knife, adding a little quartz rock to the handkerchief full of bullets he pushes across the table, or putting pennies in my eyes. The moments he added that weren’t in the script were unexpected gifts.

The scene where Jim forces two police officers to take him into custody was an important one for me. After Ryder appears and shoots the cops, the script had Jim running away from the crashed patrol car and falling to the ground, but right before the take I still wasn’t sure how I was going to play it. I scooped up some dirt and rubbed it on my face, and as I looked up into the sky the clouds happened to part and the sun hit me. Most directors would have said: “We had a change of light. Let’s shoot it again.” But Robert kept rolling. John Seale, the cinematographer, is a true artist who understands how to make a moment better. He got a separate shot of the sun coming out from behind a cloud and cut it in, so we got this brilliant moment in the middle of the movie where Jim stands up in the sunlight as if he’s been reborn.

• The restored edition of The Hitcher is on 4K UHD and Blu-ray now