The journey leading up to a riveting climax can be the greatest thing you've ever witnessed, but if the film drops the ball on translating a script to screen, the whole experience is soured.
Simple bad writing is one thing, but then there are the stories that don't leave you angry or elated, but rather have you scratching your head wondering why you just wasted two hours of your life only to be left wanting an explanation.
When the people creating the film are breaking down every frame, inside and out for months and understand their script to a tee, it's easy to miscalculate how it will translate onto the uninitiated.
Nowhere is this situation more common than the often experimental science-fiction genre. With time-travel, abstract themes, and science our puny human minds couldn't comprehend being explored in depth.
The following ten films are ones that have committed the cardinal sin of leaving their audience bewildered and racing online to find out if anyone wiser than themselves managed to figure out what they just watched.
It goes without saying, but spoiler warning ahead.
10. Prometheus (2012)
While Alien had an understandable main plot to follow and intriguingly mysterious side-content for fans to chew over, Prometheus made the mistake of making its central narrative filled with too much unexplained material.
The entire film is focussed on the 'Engineers' that are hinted to have created life on Earth, and throughout the runtime, we are given glimpses of their culture, weaponry, and abilities. The film does an exceptional job hyping them up, and when the crew finds one alive you're positively giddy to get a chance to hear what it has to say.
However, we barely get a look at the thing before it goes on a killing spree and then begins to prepare to target Earth for what we can only assume is to cause more terror. He participates in a brief fight with our lead character before getting taken out by a newborn Alien that was introduced to the film ten minutes previously.
That's it. We don't hear a single word from our creators after all that build-up and no explanation for the strange black goo, the reason the engineers disappeared, or why they made us at all. It infuriatingly just left audiences with more questions than answers.
Oh, and if you were hoping they explain it in Alien: Covenant, you're out of luck, because the engineers are wiped out within ten seconds of Michael Fassbender finding them without so much as a handshake. Go figure.