The Donnie Darko truth. Many have been baffled by the storyline to Donnie Darko, many have thought it just a mixed up film. But having watched it too many times I came to understand it.
In the film he is given a book written by Roberta sparrow (the old woman who tells him all creatures die alone) from his science teacher. From what the book says, we can understand the film. It says that once every now and then, an object (made of metal) will come to an individual. The object that came to Donnie was the plane engine. The individual will gain powers, like control of fire or water or super human strength (Donnie shows these traits when he floods the school (power over water), when he sets the paedophile's house alight (power over fire) and when he puts the axe in the copper statue in the school yard (super human strength). It also says that's the individual who receives the object will have to take it back to where it came from or they will die. The examples given were an arrow head or a sword having not been returned so had killed the individuals responsible for its return. The whole back story to the objects sent to the individual people is just that a rip in time has occurred and they have come back to the past, the individual had to return it to the future for time to heal itself. They individual is given a '3 to 4 week' life extension, to return the object. Hence Donnie Darko's dream or hallucination told him he had 28 days until the end of the world. So the whole film is based on a boy receiving an object and having to fulfil the individual's duties by returning it. He did not figure this out, and so did not take the plane engine back to where it came from, so died in order for time to heal itself.