Truman Burbank lives happily in a small, peaceful and beautiful town called Seahaven. He has a quite good job, a nice wife, and basically a happy life, until he starts to suspect that his life is a fake.
The town Seahaven is really an extremely big film studio (the Great wall of China and this dome are the only things that can be seen from space), full of cameras, in which the world's most famous reality show, The Truman Show is recorded and broadcasted to the entire world.
The main character is Truman, who doesn't know about that; everybody else are stunts and actors. Truman was adopted by the film company right after his birth, they raised him with false parents, and since Seahaven is surrounded by water and they don't want Truman to get off the island, they managed to make him hydrophobic by drowning his 'father'.
One day mysterious things start to happen - a big lamp falls from the sky; Truman hears on the radio that his actions are being reported; a total stranger calls him by his name; he sees actors change dress in a bank etc. Then he desperately wants to break out from Seahaven, but he is very well guarded.
Continuity mistake: When Marlon stocks the vending machine, the camera (inside the back of the machine) shows him stocking the 1st row with brown-wrapper candy bars. He starts stocking the 2nd row with yellow-wrapper bars; Truman interrupts him for a minute (during which Marlon doesn't touch the bars at all). When Marlon continues, the yellow bars have changed to something darker (it's not just a different camera view; even barcodes are different). After another brief interruption, Marlon continues again, and the yellow bars are back. (00:35:00)