Most current movies are so formula-driven that the only real question is how long the picture will retain its own personality before sliding into a cookie-cutter pattern.
Sometimes it takes an hour. Usually it takes far less.
And then there are times when the very first shots are so trite, tired, and worn that you know from the opening credits that you're in for another ride on an all-too-familiar caboose.
This brings us to "Twisted."
It begins with the policewoman heroine busting a bad guy with such stiff, stilted bravado that I thought it might be a dream sequence. Surely it couldn't be meant as dramatic realism! But it is.
And amazingly, the movie gets worse as it goes along.
Ashley Judd plays Jessica, a young woman whose childhood was scarred by tragedy.
Now she's a cop, working under the officer (Samuel L. Jackson) who raised her after her parents' violent deaths.
Her new assignment is to find a serial killer who "signs" his crimes with a burn mark on the victim's hand.
Yes, that's routine stuff in today's movie marketplace. So screenwriter Sarah Thorp lends the story a, uh, twist by giving Jessica regular visits to a sympathetic psychiatrist. But wait, that's hardly unique in the age of "The Sopranos."
So the screenplay adds more gimmicks, painting Jessica as a deeply flawed character - she drinks so much that she has periodic blackouts - and making each of the murder victims a man she's slept with recently.
Could she be the killer, knocking off former lovers in an alcoholic daze?
Or is it her partner (Andy Garcia) or someone else in her San Francisco precinct? Or one of the minor characters who pop up like undercooked red herrings?
I won't reveal the finale, but I will reveal that I guessed the villain's identity - and another secret from Jessica's troubled past - about 15 minutes into the 97-minute film. So much for the surprise ending.
If you're in the mood for twisting, save the price of a movie ticket. Stay home and do the dance.
• Rated R; contains sex and violence.