We see a closeup of Patrick Stewart's eye, and someone (Stewart) asks, "What's the last thing you remember?" Professor X (Stewart) responds, "I had a glimpse into the past."Then Professor X tells Wolverine, "You're going to have to do for me what I once did for you." We slowly zoom out from Professor X's aged face, and then we see him with a Cerebro helmet on, and later coming out of the Cerebro chamber.
And this is a dark dystopian future, where the dark, fetishy costumes are looking more dirty and distress and messed up, and Professor X and Ian McKellen's Magneto seem weary and filled with dread. They're in a war chamber in front of a table that shows how badly things are going. Wolverine even has a bit of gray in his facial hair.
We see flashes of all our favorite mutants, including Storm against a stormy sky, Ellen Page as Kitty Pryde, and some others. And there are futuristic-looking mutants, including Omar Sy as Bishop, and some others I couldn't identify wearing dramatic Mad Max-y makeup.
We learn that Professor X and Magneto have come together "side by side, to end this war before it ever begins."
Wolverine asks, "So I wake up in my younger body, and then what?" Professor X responds, "Find me, convince me of all this." And Magneto chimes in that Wolverine will find younger Magneto a different person, "a darker person." We catch glimpses of 1970s versions of Magneto and Professor X — with a lot more hair and a lot more fire to them. Young Professor X has a crazy beard and a 1970s groovy outfit with an X-shaped light on his face, while Young Magneto (Michael Fassbender) is waving a gun.
We see Young Professor X blowing dust off a white globe.
Back then, Professor X says, "I was a very different man. Lead me, guide me, be patient with me." We see Young Professor X putting his hands on someone's face as he tries to understand. Maybe Wolverine's face?
Older Wolverine responds, "Patience isn't my strong suit."
And then blue glowing hands are gripping Wolverine's head, sending him back in time into the body of his younger self.
We catch glimpses of other stuff — Young Magneto using his powers to pull a distressed Mystique along the floor. Young Magneto descending from the air looking scary. There is a mysterious opening under the Oval Office, revealed by the oval opening up like a trapdoor. And protests in the street, and Bolivar Trask (Peter Dinklage) addressing a government hearing. And Richard Nixon looking weird and terrifying — and then Mystique walking down the street changing into a man in a pimp suit.
There is a LOT of stuff blowing up, and Young Professor X using Magneto, and the Beast attacking, a woman walking away from an airplane, and a military setting. We glimpse Professor X shielding his face from an intense white light, and the Cerebro machine exploding.
Young Professor X says, "I don't want your suffering. I don't want your future."
And then Old Professor X is face to face with his younger self. He says: "Please. We need you to hope again." It's an actual spine-tingling moment. Actual goosebumps here.
The footage kicks off with Xavier’s voice before cutting to shots of the Singer X-Men: Wolverine, Storm, Iceman, Rogue, Kitty Pryde, described as a look into the past.
Seems almost like it’s Bishop’s “X-traitor video,” used so often in the comics. It might be since next we get Bishop, Thunderbird and Blink.
“Side by side to end this war before it ever begins,” Xavier says, and we see that he’s teamed with Magneto.
“I was a very different man. Lead me, guide me, be patient with me,” he tells Wolverine, who responds, “Patience is my strongest suit.”
Then we see Mystique in combat, a bunch of shots, including fighting Magneto.
“We need you to hope again,” Patrick Stewart’s Xavier to his younger self.
UPDATE! Per Slash Film:
The footage opens on an eye. Professor X’s eye to be exact.
“What’s the last thing you remember?” he asks in voiceover. (All quotes below are voiceover unless noted.)
A montage of several original characters: Shawn Ashmore as Ice Man, Ellen Page as Kitty Pride, Halle Berry as Storm. etc.
“I had a little glimpse into the past.”
Wolverine, dressed in a black outfit fitted with buckles, walks with older Professor X (Stewart) and older Magneto (McKellen), in similar attire. They appear to be in some kind of temple, with very rich colors.
“You’re going to have to do for me what I once did for you,” Xavier’s voice says. “You need me as well,” Magneto adds. “Side by side to end this war before it ever begins.”
The trio approaches what appears to be some kind of ritual table, followed by a montage of new characters including Omar Sy as Bishop. They appear to also be in this present/future time with the original characters, in similar black outfits.
“So I wake up in my younger body and then what?” Logan says. “Find me. Convince me of all of this,” Xavier explains.
We finally see the younger Xavier (McAvoy) sitting down with an ‘X’ of light on his head. He and his companions are all in ’70s clothes.
“It’s going to take the two of us,” Magneto says.
Now we see young Magneto (Fassbender) floating, doing some other possibly sinister stuff.
“Then where do I find you?” Logan asks. “On different paths,” old Magneto says. “Darker paths.”
We see some more shots from the ’70s, most of the new First Class characters living their own lives.
“Logan, lead me. Guide me. Be patient with me,” the older professor pleads. “Patience isn’t my strong suit,” responds Logan.
We see Logan with two lights on the side of his head and he screams. Hard cut.
The footage goes into a montage of many things. Some examples include a secret compartment under the Oval Office. More new characters. Trask (Peter Dinklage) presiding over a meeting. Lots of action scenes including Wolverine riddled with bullet holes, Mystique (Jennifer Lawrence) crying, Mystique changing form and walking in a military uniform, Young Magneto floating, getting choked by Beast (Nicolas Hoult) and young Xavier blowing the dust off Cerebro.
Finally we see young Xavier touching Logan’s face and we hear his voice in voiceover, from a different scene.
“I don’t want your suffering,” Xavier screams. “I don’t want your future!”
The final shot is young Xavier encountering old Xavier, looking each other dead in the eye, and old Xavier says the following as voice over:
“Please. We need you to hope again”
Then the title card: “Days of Future Past.”