Warning: Definite (altered) TOS references.
The night following the help McCoy administered to the injured Shii'reti woman, he had a strange dream. He remembers floating above his body (disassociation, says the medical mind) into whiteness, which wasn't right because space should be black. And empty. This place was not empty, because he could make out a round form, though hazy. Green. Blue. Green, blue. Beautiful.
Familiar.
My God, is that a planet? My planet? He remembers the shock of knowing it was Earth.
Lazily, he reached out (you're asleep, Leonard) a hand and shivered as electricity stung his fingertips. Low rumbling shook his eardrums.
And Earth cracked open, spilling bright hot red into the blue green—split apart (right through the middle of the Pacific) and Bones watched, horrified, as it imploded into whiteness.
He woke up with a severe headache behind his eyes.
The next night, immediately upon lying down, he was flung from his body again. But the vision was not true white, it was Sickbay-white.
What the blazes am I doing in Sickbay?
"Doctor McCoy! Doctor McCoy! We're losing him!"
He spun towards the voice, and when he saw the biobed (why is there only one biobed, no nurses?) Leonard thought he was going to throw up.
The greyish (bloodless) body belonged to Jim. He recognized the strong, now curling, hands and short square nailbeds; he knew that stubborn jaw line, what little was not covered by destroyed flesh.
But his golden hair had mostly fallen out, his face and body supporting open, gaping radiation burns. His eyes—God, those bright eyes—were filmy white (fried).
Jim, Jimmy-boy…
McCoy choked down bile, his hands shaking with emotion.
"The radiation destroyed him cell by cell, Doctor."
Bones couldn't lift his head to see who had spoken. "What radiation? What happened?" to my Jim?
"He sacrificed the one for the many—to save us all."
At that, Bones drew back to retort (how can we be saved if he's dead!) but he stopped short.
A female with green hair and cold, cold eyes smiled at him.
"What the hell is going on? You're not—"
"I am here."
"This… this isn't real! Get out of my head!"
"This is the truth," she said and reached out to him. Bones stared at the long gash in her arm, dripping white. "You're bleeding the truth too."
He looked down at himself and bit back a scream. White blood poured from slits in his forearms.
He woke up, carefully slid from the bed, and laid his forehead down on the cool tile of the bathroom.
McCoy did not sleep the next night, which did little good. The third dream (not dreams, Leonard's heart argued) came during the day. He had been making a pot of honest-to-God real coffee, when he reached for the tin of grounds and grabbed only air. The kitchen counter had disappeared too.
Instead, the doctor was facing the open campus of Starfleet Academy. Shots rang out in rapid succession, startling him from his disbelief and he realized he was in the middle of a ceremony.
When the horns began to play, he knew with dread he was at a memorial service. Rows upon rows of people were standing. Some were weeping openly; others, stoic in their laments.
A disembodied voice droned on, "In honor of the late Captain Spock, son of Sarek—a Federation hero, brilliant scientist and—"
"—another of your lovers," the Shii'reti smiled over at him and took his slack hand in hers, "dearly departed."
"I helped you. Why?" Leonard struggled to hold himself together. "Why are you doing this to me?"
She said, "The Nexus took him, and now you'll never get him back."
"Why, God dammit!" He jerked his hand away and faced her. (She started to glow.)
"We see only the truth now, McCoy."
He would have replied (scathingly) but Leonard was in the kitchen again, with a faint echo of laughter in his ears.
He had thrown the coffee out, grabbed his jacket, and left in search of his sanity.