Trailers have been around almost as long as feature films, titillating audiences with smorgasbords of spoiled surprises: explosions from action movies, jokes from comedies, lovey-dovey bits from romances. What’s not to like about pint-sized pastiches of scenes, plots and people capable of making even Rob Schneider comedies momentarily palatable?

A creative dilemma exists in the process of a trailer’s construction that every film buff has grappled with at one point or another. The obvious inclination for an editor is to wrap together the best bits: the money shots, the zingers, the punchlines, the beautiful horizons. If you’ve seen a trailer for a comedy that has only a handful of good gags, and all are in the promos, you’ve seen the best bits of the movie well before coughing up for admission and popcorn, and the cinematic experience invariably suffers.

The worst kind of trailers don’t reveal mere moments, but entire storylines. This is particularly problematic if the film in question hinges on the progression of plot — a thriller, a whodunit, a mystery, or simply a story predicated on an unresolved event (i.e. a person gets lost at sea; a killer’s master plan is incomplete).

The two-and-a-half-minute spoiler dump for Robert Zemeckis’ Cast Away (2000) is among the worst of them. We see Tom Hanks’ life, pre-disaster; we see the plane crash that strands him; we see him getting shaggy and desperate on a desert island; we see him escaping said desert island. If that wasn’t enough, the final image of the trailer is exactly the same shot as the final image of the film.

I try to avoid trailers and “go in cold” as much as I can, but a mistimed entrance into the cinema presents a trio of grim options: you can sit down and suck it up, bolt for the exit or close your eyes and put your fingers in your ears (hardly the look of a dignified critic).

I recently sat through a trailer for The Call (watch it here, or scroll to the bottom of this post), a thriller in which Halle Berry plays a 911 call centre operator who becomes, in the Angela Lansbury on a bicycle tradition of unqualified investigators who stick their beaks in places they are not wanted, instrumental in tracking down a serial killer. It seemed to take particular satisfaction in revealing every major plot point, leaving little to no room for surprise. But was that just me being cynical or merchants of the spoiler devils doing their dirty work?

I decided to put this to the test, in a lab coat-and-clipboard kind of way. I came up with the following plan: I would watch The Call’s trailer a few times, take some notes, and write a series of predictions — some broad, most fairly specific — then compare them with the actual movie to discover whether I had accurately predicted it based solely on its advertising. When I arrived at the cinema, I brought with me a strange sensation I’d seen this movie before. That, if someone were to ask what I thought of it, my response would be “an expendable by-the-numbers thriller sufficient for unfussy audiences, but certainly nothing to rush to see.”

Below you’ll find a series of notes split into three areas: a description of what the trailer reveals, my prediction based on this moment in the trailer and the verdict on whether or not I was right. Naturally, like the trailer, this post contains spoilers.

TRAILER
Sporting a lovely Whitney Houston cut, Halle Berry takes a call from a panicked young girl who tells her a stranger is in her house. The call disconnects, so Berry — the first of many actions certain to turn real 911 staff beetroot with incredulity or have them happily revelling in the fantastic disconnect between movies and reality — calls her back. The stranger hears the phone ring, evidenced by the girl saying “I think he heard the phone ring.” She is dragged from under the bed. The phone is still connected. Berry cautions the man: “I suggest you leave the house before you do anything you’re going to regret.” He says “it’s already done.”

PREDICTION
It’s not already done. When he “does it” we see a violent act shot in dim light. The criminal’s face is not revealed.

VERDICT
Correct.

TRAILER
A text insert appears: “WHAT IF YOUR MISTAKE COST SOMEONE THEIR LIFE?”

PREDICTION
Halle Berry’s mistake costs someone her life.

VERDICT
Correct. A young, pretty, blonde-haired, virginal girl is killed because — as Gene Hackman memorably put it in Tony Scott’s Enemy of the State (1998) — “you made a phone call.”

TRAILER
Berry watches a news report covering the girl’s death. The reporter says “this marks the sixth girl murdered. Investigators believe they are dealing with a serial killer.”

PREDICTION
They are dealing with a serial killer.

VERDICT
Correct.

TRAILER
Berry is on a balcony, gazing forlornly into the city skyline.

PREDICTION
A handful of scenes depict Berry, wracked by guilt, moping about looking exasperated and deflated. Her hair reacts by sagging ever so slightly towards the ground.

VERDICT
Correct (but not 100% sure about the hair). Berry awakes in the middle of the night covered in sweat. She returns to work, feeling the heavy gaze of colleagues who stare at her with “what have you done?” stamped across their faces. She takes anxiety pills to deal with her guilt. She is now a call centre trainer who gives new recruits advice such as “stay emotionally unattached and never make promises,” ensuring her character will go on to become emotionally attached and make promises.

TRAILER
On the balcony, a police officer gently rubs the side of her neck. He says “I’ll be here when you need me. You know that, right?”

PREDICTION
The cop and Berry have been involved in an emotionally challenging relationship in years or months prior to this moment. They were dating or shared a traumatic crime-related experience. A new traumatic experience related to the aforementioned serial killer brings them back together.

VERDICT
Incorrect. They are dating. Should have seen that one coming.

TRAILER
A young pretty girl is kidnapped in a car park. She is thrown into a trunk. Inside the trunk she makes a 911 call. The panicked operator at the call centre says “I don’t know what to do.” Berry looks on, worried.

PREDICTION
A mess of conflicted emotions, Berry pulls herself together and hesitantly takes over the call, compelled by a subconscious desire to forgive herself for what happened last time.

VERDICT
Correct. Despite stuffing up previously in the worst way imaginable, and being rightfully stripped of her duties, Berry’s colleagues entrust her with the most important call they’ve had since the last one she botched.

TRAILER
We’re on a freeway. Berry advises the girl in the trunk to “kick the tail light out” because she wants to know “if any other cars will be able to notice you.” The girl’s hand dangles out from the rear of the vehicle, flailing in mid air, like an arm from a kind of quasi Cronenbergian human/car hybrid.

PREDICTION
This dramatic moment is unintentionally hilarious, and the best part of the movie — albeit one that disappears far too quickly.

VERDICT
Partially correct. Berry’s line “I need you to stick her hand out and wave it, wave it, wave it” amuses but the movie is stubbornly humourless. Even the ridiculous bits (there are several) are played with dryer-than-desert deadpan.

TRAILER
At a gas station, the girl escapes the trunk and crawls through to the back seat of the car. An attendant sees her and demands the killer open the car door. The killer responds by dousing him with petrol and setting him on fire.

PREDICTION
After a couple of seconds watching the attendant run around like a human fireball, the killer says a smug one-liner such as “keep the change.”

VERDICT
Incorrect. The Call really doesn’t have a sense of humour.

TRAILER
The killer has his second conversation with Berry. She says “you don’t have to do this.” He replies “it’s already done.”

PREDICTION
Again, it is not already done. Berry will spend the rest of the running time doing her darndest to ensure it will not get “done.”

VERDICT
Correct.

TRAILER
In an ingenious stroke of detective work, Berry realises it’s the same man, indicated by the following line of dialogue: “it’s the same man.”

PREDICTION
It’s the same man. And this time, it’s personal.

VERDICT
Correct. In a twist that will surprise only those with an IQ smaller than their shoe size, or who spent the first slab of the movie making out or trying to find a parking spot, it is indeed the same man.

TRAILER
Sitting in his car, a man in a business suit notices suspicious activity and calls 911. His window is smashed.

PREDICTION
The killer is once again reminded of the annoying proliferation of mobile phones. He silently contemplates what life would have been like in “the good old days” for serial killers, when people didn’t carry devices capable of immediately alerting authorities. He kills the driver by bludgeoning him on the head with something.

VERDICT
Correct. The killer’s weapon of choice is a shovel.

TRAILER
Police storm a “normal” looking house in a middle class street.

PREDICTION
This is not the house of the killer. It’s a trap. The house is rigged with explosives, and the ensuing blast kills the man with whom Berry once had a relationship. This makes her mission to apprehend the serial killer Even More Personal.

VERDICT
Incorrect. It is the killer’s home. However, he is not there. The main cop discovers clues about the location of the killer’s secret lair but doesn’t put all the pieces together.

TRAILER
Police storm a different, grungier, more evil looking house late at night. This is followed by a shot of Halle Berry opening the door of said house and peering inside, waving a flash light.

PREDICTION
After doing some detective work, Berry speeds off in her car and arrives at the killer’s hideout.

VERDICT
Correct. Her detective work involves listening to phone recordings repeatedly. She locates a hidden underground lair.

TRAILER
A series of rapid shots depict moments of carnage, including a close-up of the killer looking at a mannequin with a streak of blood on it.

PREDICTION
The killer kidnaps pretty young girls and models mannequins that look exactly like them, for some weird half-explained reason. While shaping his latest masterpiece he says to his bulging-eyed victim something like “you will look more beautiful in death than you ever could in life.”

VERDICT
Incorrect. The killer is entirely concerned with his victims’ hair. This is for reasons that, if you’re still reading and still somehow receptive to the idea of sitting through The Call, I will leave for you to discover. You’re welcome.

TRAILER
Berry is spotted hiding in the killer’s lair. They fight. He dunks her head in a sink; she kicks and flails.

PREDICTION
Berry outsmarts and/or overpowers the killer and prevails in the end.

VERDICT
You know the answer to that.

And now, the findings. But first a score check: I got ten predictions correct, four incorrect and one partially correct. The predictions I got wrong tended to be bolder than the ones I got right — but hey, it would have been glorious if that house had exploded and blown Berry’s beau to bits.

So did the trailer spoil the movie?

Yes and no. The Call turned out to be unusually entertaining as a mystery, but in a different sense than director Brad Anderson would have intended. The exciting part of the mystery was ascertaining whether the trailer left any mystery at all. The results, as indicated above, were mixed.

And my verdict on the film, if you must know? I’d hesitate to recommend a genre pic as stock standard as this one. I’d probably describe The Call as an expendable by-the-numbers thriller, sufficient for unfussy audiences but certainly nothing to rush to see.