Thor Odinson watches as Peter Parker and Pepper Potts cry over Tony Stark's unmoving figure. He notices that the rest of the Avengers are grieving over Tony's death, but Thor doesn't let himself succumb to sorrow while there is still a chance that he can save Tony Stark.
So with that thought in mind, he walks towards the place where Thanos was sitting right before the Titan turned to dust. He sees the red gauntlet they created from Tony's nanotech on the ground. He picks it up and places it over his hand. He observes how the nanotechnology easily assembles to fit the gauntlet into his hand.
Afterward, he walks to Tony's dead body and starts picking up the Infinity Stones with the intent of putting it into the gauntlet in his hand.
"What are you doing Thor?" Thor hears Steve Rogers ask from behind him.
"What do you think?" Thor responds.
There is a momentary silence as Thor continues to place the rest of the Infinity stones into the red gauntlet in his hand.
"Do you think it will work?"
Thor hears the boy - Peter Parker - inquire with obvious hope in his voice.
"I'm not sure, but at least we need to try," Thor says solemnly as the final Infinity stone snaps into place.
Thereafter, he turns to the rest of his comrades and says, "I'll bring him back."
Then, he snaps his guantleted fingers and Thor only knows pain.
"Thor!"
He hears someone yell his name but he is in so much agony that he nearly loses consciousness as the Infinity stones sap his strength.
Later.
When he finally comes to, a familiar figure is standing in front of him and he realizes what happened.
"I gather it worked then," Thor says with a pained smile.
"Yes, it did buddy," Tony Stark says with a grin. "Thank you Thor."
Thor nods his head and responds, "I'm glad your back."
"I'm glad to be back as well," Tony says right before he adds, "So who wants to go for Shawarma after this?"
AN: I still can't get over the fact that Tony Stark is dead. So this is a fix-it of sorts for the final ending.