The movie "From Dusk Till Dawn"

I watched this movie “From Dusk Till Dawn". I could not understand this movie. The first half of this movie is a serious crime suspense movie. But the latter half is a horror movie. I could not catch up with the sudden change. The leading role is played by George Clooney. Quentin Tarantino is also playing an important role. However, Cheech Marin plays three different roles in this movie. I decided to watch this movie because George Clooney and Quentin Tarantino play in this movie. But I was disappointed by the movie. If I were a ardent fan of Quentin Tarantino, I could enjoy this movie.