Phoenix

Answer: According to the DVD special features, people who die in the alternate universe (the Manipulated Dead) have more power and self-awareness than those who live throughout. The supernatural force that appoints Donnie to end the alternate universe adopts Frank's face because a) he wants a form that Donnie can interact with and b) as a Manipulated Dead Frank has more understanding of what is going on and maybe wants to help. The costume is necessary because it's an essential part of Frank's character as a dead person - it's what he was wearing when he died - and also because it's so alien Donnie will understand that he's dealing with things beyond normal ken.

Phoenix

Answer: Frank calls Donnie out because the airplane engine has fallen through a portal into an alternate universe, and at some point during his sleepwalk Frank guides Donnie through another portal to move him to the alternate universe (from the movie theatre we know that Frank can make portals at will). Frank appoints Donnie to be the guardian of the engine and make sure it falls through the alternate universe's portal into the original universe. Donnie cannot be allowed to die until the engine is escorted into the second portal, but if he dies before then the engine never reaches the second portal and remains in the alternate universe, causing the original universe to unravel. Once he and the engine return, he must die because his experiences of the alternate universe predict the future, potentially causing paradoxes.

Phoenix

Answer: Frank tells Donnie to burn down Cunningham's house because then Cunningham's kiddie porn dungeon will be discovered and he will be put on trial. If he's on trial, Kitty must be at his arraignment and cannot escort the dance team to Los Angeles, so Rose goes with them instead. Rose chooses to come home with the team on a different flight than Kitty would have chosen, and if they hadn't been on that flight the flight wouldn't have occurred (we don't know why not, but if it happened anyway Donnie wouldn't be necessary, and he obviously is or Frank wouldn't have called upon him). Because Rose takes the flight, the airplane engine passes through the portal and falls into Donnie's bedroom back in the original universe, closing the time loop.

Phoenix

Answer: The "end of the world" refers to the end of the alternate universe Donnie enters when Frank summons him out of bed at the beginning of the movie. The alternative universe will only last until the airplane engine is returned to the normal universe and Donnie dies. Donnie sets in motion events that lead to the airplane engine falling through a portal to the normal universe, and when it finally returns he defaults to his place at the exact point when Frank summoned him out of there to guard the engine.

Phoenix

Answer: Frank never goes back in time. In a special feature on the DVD called The Philosophy of Time Travel, there is an extensive discussion of what happens when an object slips out of the proper time continuum through randomly occurring portals. Forces exist to ensure that the object has a human guardian, whose responsibility it is to return the object to a portal in time that will send it back to the proper continuum, often sacrificing the life of the guardian. Frank, in the movie, is both a rather unimportant human figure and the adopted face of the force guiding Donnie to his destiny (returning the airplane engine) that exists outside of either time continuum and can speak to the inhabitants at will. The only thing he directly tells Donnie to do is to burn down Cunningham's house, which results in Cunningham's trial and causes Rose to take Kitty's place escorting the dance team to LA, and Rose chooses to take an earlier flight home. This is the only way the airplane engine would have been in the portal to be returned to the proper continuum. The other violent things Donnie did were merely satisfying his own issues with school, his girlfriend, and her death.

Phoenix

Answer: Throughout the film, themes of alienation and disillusionment are prominent - an illustration of the alternate universe plotline. Cherita is that theme manifested in a very visible sense - people make fun of her, reject her, and she obviously doesn't fit in.

Phoenix

Answer: Cherita's seemingly small role has larger implications and can be used as a contrast effect to Donnie. Cherita liked (loved?) Donnie, but she could never be with him because they are from two "different worlds." But this does show that people with "mental problems" can be and often are attractive to others. Many teens feel alienated but for different reasons. Cherita and Donnie didn't fit in well. Cherita was teased/bullied by teenagers who went to a private religious school. Surely they have heard the expression "do unto others..." Why is this bullying behavior not viewed as mental illness while some other behavior is? Donnie told Cherita things would get better for her. After the teenagers graduate and mature, they will outgrow the behavior and the teasing should cease. Cherita doesn't need to change in order to have a better future. The same is not true for Donnie - he is not likely to outgrow his mental illness, and unless there are major changes in him, he will have no future.

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