A spine tattoo, a bite mark and a detective who never asks about either. Why the loose ends we’re shown are so much harder to forget than the stories that tie up neatly.

About three years ago, I watched a film that irritated me so much that I still think about it at least once a week. 

The film in question is the 2023 Netflix thriller Reptile, directed by Grant Singer and starring Benicio del Toro, Alicia Silverstone and Justin Timberlake (who acts well enough but unfortunately cannot escape looking like he is about to start crooning at any minute). Beyond its cast of familiar faces, the film offers a tantalising premise: a young woman with a complicated past is found murdered in an empty showhouse, and it is up to the broody, grizzled detective (brought to life by Mr del Toro, of course) to untangle the threads and bring a killer to justice.

This isn’t exactly new storytelling territory. If anything, Reptile relies on a series of familiar tropes that have earned their longevity because they just work, time after time. All the makings of cinematic success were right there. 

If this film had been good or even average, it would have retreated to the back shelves of my mind by now. But it wasn’t good or average – it was bad for such an incredibly specific reason that my mind keeps returning to it involuntarily, in the same way that the tip of a tongue seeks out a niggly popcorn shell trapped between teeth. 

There’s a reason why I can’t let this dumb film go, and it has a lot more to do with the human condition than you think. 

Chekhov’s Gun, unfired

In order to explain, I need to introduce you to a man who died more than a century before Reptile was made, and who would almost certainly have hated it as much as I did.

Anton Chekhov was a Russian doctor who wrote short stories and plays on the side and eventually became one of the most influential writers of the modern era (side hustlers, take note and have hope).

In 1889, he wrote a letter to a younger writer, Aleksandr Lazarev, with a piece of writing advice. The most widely quoted translation reads: “One must never place a loaded rifle on the stage if it isn’t going to go off. It’s wrong to make promises you don’t mean to keep.” 

That’s the principle that became known as Chekhov’s Gun. If a story – whether written in a book, played on a stage or filmed for the screen – shows you something that seems important, like a locked drawer, or a character who gets a lingering close-up and then a single meaningful look, it has to pay off.

Every detail is a promise, and a good storyteller keeps their promises.

When we sit down with a book or a film, we hand the storyteller our attention on the understanding that they won’t waste it. We notice the (metaphorical) gun, we file it away and we wait, slightly tense, for the moment it goes off. When it does, there’s a click of satisfaction, like the last piece of a puzzle pressing into place. 

But when it doesn’t, we’re left waiting and wondering why our attention was fixed on this detail in the first place. That sensation is known as Chekhov’s Gun unfired, and it is the sum of every issue I have with Reptile. 

The non-existent snake in the grass

Midway through the film, the soon-to-be-murdered victim undresses in a gym locker room. The camera lingers on her exposed back, which features an incredibly large and distinctive spine tattoo that kind of resembles the pattern you might find on a snake. In a film called Reptile – which, as far as I can tell, contains no reptiles whatsoever – this felt significant.

“Aha!” I thought.

But alas, no.

This tattoo, so painstakingly brought to my attention (the locker room scene exists almost solely for it to be revealed), is never seen, acknowledged or mentioned by any other character.

At her autopsy, the coroner says to the detective, “Can I show you something strange?”

I wait with bated breath for the body to be flipped over and the tattoo to be discussed. Instead, I am shown her hand, which has a human bite mark on it. The detective discusses it at length with his wife, even re-enacting the bite on her hand to check the position, and then it is never mentioned again.

Not even when the killer is eventually caught.

To be fair, unanswered questions don’t always mean a story has failed. Some of the best stories leave things unresolved on purpose, and they trust us to sit with the uncertainty (looking at you, Inception). But there’s a difference between a story that chooses not to answer and a story that seems to have forgotten you asked.

And now, three years on, it’s the tattoo I think about, and the bite. I couldn’t tell you how the film ended without looking it up – something about drugs and property fraud – but I could draw you that spine tattoo in reasonable detail.

Why are we like this?

In 1928, a psychologist named Maria Ovsiankina ran a simple experiment to try and answer that very question. She gave people small tasks to do and interrupted them partway through some of them. Then she left them alone with a choice: either start a new task, or go back and complete one that was interrupted.

Most participants chose the latter. With no reward and no one telling them to, people went back to the tasks they hadn’t finished, as if something were pulling them there. This became known as the Ovsiankina effect, and almost a century later it’s still holding up. A 2025 review of decades of research found that when people were given another opportunity, they often returned to an interrupted activity before moving on to something new. 

The urge to finish what we’ve started seems to run deep (just ask any toddler parent and they’ll confirm it). An unfinished thing isn’t content to sit quietly in the corner of the mind. It tugs at your sleeve and asks you to come back.

So how do we let go?

In 2011, psychologists EJ Masicampo and Roy Baumeister set out to find out. They found that an unfinished goal kept intruding on people’s thoughts until they made a specific plan for how they would finish it. Note: not finishing it, just planning to finish it. Once the mind was satisfied that the task was in hand, it seemed willing to put it down.

The catch, of course, is that some things can’t be planned to completion. Nobody is going to explain that tattoo to me. There will be no director’s cut in which the coroner finally turns her over. Some guns are never going to go off, and perhaps the hardest part of letting go is accepting that the story was never ours to finish in the first place.

We don’t go back to everything we leave unfinished, only to the things we cared about. Which means, I suppose, that Reptile did succeed at one thing: it made me care enough to be annoyed for three years.

About the author: Dominique Olivier

Dominique Olivier uses her love of storytelling and ideation to help brands solve problems.

Her first book, Lessons from Loss, has been published by Penguin Random House.

She is a weekly columnist in Ghost Mail and collaborates with The Finance Ghost on Ghost Mail Weekender, a Sunday publication designed to help you be more interesting.

You can learn more about her work at dominiqueolivier.com and she can be reached on LinkedIn here.