Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

In the film The Prestige, Borden's secret is that    He has a twin brother.   Watching the movie for the second time, I noticed a man looking just like Christian Bale sitting next to Borden at the beginning of the scene where Angier and Borden appear as assistants.  Am I mistaken, or is the secret revealed as soon in the movie?
Is Borden's secret revealed as soon as the 11th minute of the movie?

Maria and Nicholas existed in Trevor's daily delusion because of his guilt about the past hit and run.   But how come Ivan exists in his imagination?   Are there any clues in movie that can prove Ivan's actuality in Trevor's past? Or is Ivan's figure totally delusional as in schizophrenic people?
How come Ivan exists in the Machinist?

In the Avengers movie everyone seemed to know a great deal about the Tesseract. Even Hawkeye seemed to know that it is a thing which can make portals (he tells about the Tesseract that door can open from both sides). In Captain America The First Avenger Red Skull only used the stone for harnessing power. So how does everyone know about the Tesseract and its capabilities?

How does everyone know so much about the Tesseract?

