Locke and Desmond are my favorite characters on Lost and I have an interesting take on how Desmond's role on the show might work.
Desmond was told by Eloise that "the island isnt done with you yet".
It appeared as if the producers were setting up The Variable to be an episode which might have hinted at Desmond's return to the Island. It was not. If anything, it was almost a solidified ending to his story. Whether or not this has anything to do with Henry Ian Cusick's legal issues, is beyond me.
Anyway, I definitely can see Desmond teaming up with Charles Widmore. Why? "because there is a war coming." LOST sets up many rivalries and ultimately pairs the two together. This could be the next step.
Desmond's brother in law, Faraday, told him that he was special, and different, but that didn't really go anywhere. Desmond delivered the message to Eloise and it appeared it was unnecessary. Did anyone else find it odd that the cliffhanger for the season 5 premiere ultimately went nowhere?
I think it was set-up for Desmond's role in the final season. Desmond is going to be forced to return to the Island. For what reason I don't know. They finally paired Penny and Desmond together happily. The next logical step in the narrative is to leave it be or bring drama and tragedy to the table.
Desmond experienced the fail-safe key implosion. This same event can be compared to the final moments of Season 5. If the '77 Losties find themselves in a timeline that isn't "correct", could Desmond be the only person capable of communicating with them, or even saving them?
My theory really pushes the importance of Desmond, but there has to be more to his story.
In the timeline that is known, Desmond crashed Oceanic 815.
If another timeline exists or if it is changed, it would be poetic, or even scientific, for Desmond to be the one to "return" the 815ers to the island.
The real question is did the Jughead Explosion change Desmond's timeline? Or is it really like Miles said, was everything they did, already done?
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(Side Theory)
I'm going to go off on a tangent here. The Season 5 finale showed that Jacob can "bring" people to the island. So maybe it wasn't Desmond's doing at all.
If you think about it. The finale showed the '77 Losties trying to stop the scientific reason for the crash. It also showed Jacob's touch. The question is, what really crashed Oceanic 815?
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(back to main theory)
Eloise specifically said that "the island isn't done with you yet". It is quite possible that The Island's plans for Desmond do not involve him returning to the Island. Meet Kevin Johnson showed that the Island's power reaches farther than itself.
I brought up before that Widmore would play a role in Desmond's storyline. A lot of people assume that Widmore wanted Locke to return to the island FOR Esau/Flocke/MIB. I think Widmore is on Jacob's side. He has been built up as this terrible person but I believe Ben has committed more acts of terror than him. Ben and Widmore seem to be at opposite ends of the game. Ben is now on the side of MIB.
Widmore and Desmond having to work together is something that just clicks for me. The only reason I can think for these two to REALLY invest in teamwork is if Penny is in danger.
Sorry if I have been all over the place, here's a little quick rundown.
- Desmond's unique abilities could help communicate/rescue the Losties from an ALT timeline.
-Widmore and Desmond's relationship has to have some form of conclusion, probably with them working together.
- The Island isn't done with Desmond.
- It is possible that the Swan really had no power in 815's crash, it was all in Jacob's touch.