Disjointed movie plots

[pecksniff]

From Dusk Till Dawn: Starts out as a standard Tarantino crime story -- but then, halfway through, there's vampires?!

2001: A Space Odyssey: At the beginning and end we have this standard SF plot about extraterrestrials manipulating human evolution. Sandwiched between, we have a completely unrelated standard SF plot about a rogue artificial intelligence. WTF?!

Any others?

 

[pecksniff]

What was your motivation to post a useless thread?

Aren't they all useless?

 

[RoryN]

Malice (1993).

Has ridiculous plot twists and abandons one plot point altogether. It's an almost-legendary mess.