The Prestige

I just saw the movie version and I understand it deviates a bit from The Prestige book version. Even with two unreliable narrators it moved along until the end, which made absolutely no sense. So please help me sort this out. The twin brother was executed, but Michael Caine's character had been helping him and turned against Angier? And Angier got shot in the end for what reason and why would he want Borden's kid? Why would Angier shoot his duplicate and who actually drowned in the tank in the first place. What happened to Scarlett Johannsen, she just disappeared? And who was floating in the tank in the final shot? I don't expect things to be tied up neatly, but this seemed to go off the rails in the last 10 minutes. David Bowie made a fantastic Tesla though.

Have you read the book, because the film was more than just a slight deviation.

I felt the film was so different from the book that both can be enjoyed separately.

SPOILER WARNING!

The body in the tank was the magician. The machine did not simply transfer someone to another place; it made a duplicate. To prevent there being many copies of the one person the tank was devised to drown the original leaving only the replica alive.

The book explains this much more readily.

I'd have to rewatch the film to answer your other questions.

So why if the clone was an exact replica wasn't he wise to the fact that he was about to be murdered by his creator?

I've wondered that too!

I think the clone always believed he was the original. (Have not read the book, though; have only seen the movie.)