Film just fades to black & ends outa the blue

Most of the ending.

Was the second timeline even real? Did DD use telekinesis to extract the chunk of plane, to send back to the original timeline? Was it a duality of schizophrenia - a message about medication? Too wacky; I adore it though.

There are a lot of writeups on the film with varying degrees of depth. This was always my take:

In a nutshell, the second timeline is what's real. However, for most of the movie we are following a tangential timeline.

The film asserts that wormholes are viable methods of time travel, but the catch is they are impossible to predict in their location/frequency and you also need some sort of "vessel" to utilize said wormholes. So basically, Donnie stumbles upon the awareness of a specific wormhole incident: the plane engine falling into a wormhole that empties out just above Donnie's room.


Whether he achieves this through schizophrenia or something else is secondary. The fact is, that reality (at least for Donnie) seems to be skewed around the incident in a sort of vortex. He picks up on temporal interference surrounding the event especially after he survives the plane engine. He even glimpses a view into "God's channel" (as he describes it when talking to his science teacher) as shown when he sees the clear bubble things coming out of everyone's chests.

It's all a bit heady and they were stretched bare-thin on their budget, so it was hard for them to illustrate this high concept stuff (the director mentions on the commentary that the clear bubble CGI was done almost completely for free). But in the end, Donnie realizes that he himself can be a "vessel" although this isn't really explained how. He chooses to "fix" his timeline by removing himself from the equation, utilizing the wormhole loop to die in bed instead of sleepwalking. I believe he was also doing this not just to save his girl, but also himself. In the crazy old lady, he saw a future version of himself: alone, paranoid, and paralyzed by the "philosophy of time" (notice that the book she wrote is the "philosophy" of time travel). She is likely a person who had an incident similar to Donnie's, but has been driven mad by it.

There's a point in the film where his therapist admits that his medication is actually placebo. Also, when he dies, we get a montage of all the other characters waking up. Frank feels a pain in his eye, Donnie's therapist looks worried, etc.. There was definitely more going on than just in Donnie's head. There is a temporal shift that everyone feels, but can't quite comprehend.

Donnie went off his meds, wandered to the golf course directly saving his life. But in the end he is killed anyway. Never stop taking your meds, kids.