(Note: Also posted on Ao3.)

No one else was on the road. Not a soul to be seen, at least as far as Cade could see—just miles upon miles of fields, the crops lush and green beneath the sun's rays.

He had Optimus Prime all to himself.

"I still can't believe you're here." His heart was swollen with joy as he gripped the steering wheel. It felt exactly as it did beneath his palms all those years ago, when life as he knew it had changed forever. "I…I was so sure I wouldn't live long enough to see you again."

"For the longest time, Cade, I thought the same." The deep voice coming from the radio was just as Cade remembered it, too. It was almost like Optimus had never left. "But I am here, now, and I do not intend to abandon you ever again."

A lump of emotion lodged itself in Cade's throat. "Good, 'cause I really missed you."

The passing scenery was becoming a blur, they were driving so fast. Instinctively he squeezed the wheel tighter, unwilling to let go.

"The world's gone to shit since you left," he went on. "God, it's…it's been so rough, Optimus, you've no idea." He paused, then smiled and gave the wheel a pat. "But now that you're back, everything's gonna be okay again! Right?"

Optimus was silent. So was his engine, Cade suddenly noticed, even though the speedometer read 90, going on 100.

"…Right, big guy?"

Dusk was falling. Thousands of stars were coming out. It was a beautiful sight to behold. Too beautiful to be real.

"Cade." This time the Prime's voice boomed all around him, nearly sending Cade flying out of the driver's seat. "Cade, something is wrong."

His stomach lurched. "Huh? What is it?"

"I do not know." The way he said it sounded familiar, but Cade could not figure out why. For what felt like an eternity he was quiet once more, but when he finally did speak again, it almost did not sound like him. "Look."

He peered through the windshield, then gasped. Straight ahead and coming up fast was the end of the road.

No.

The end of the world.

150, read the speedometer.

"Stop, stop!" Cade slammed his foot on the—floorboard? What the fuck? "Optimus, your brakes! I-I can't…where are your pedals?"

The steering wheel slipped out of his grip. His entire world tumbled around him. There was one second of weightlessness, and in the next, he found himself in a giant metal hand. He hugged one of the fingers for dear life before his brain even registered what had just happened.

"It is all right," the bot's voice rumbled above him, hauntingly calm and sad all at once.

All right? How could that be? Optimus had transformed to stop himself, but the terrifying speed was still pulling them closer and closer to the precipice. Beyond was nothing but a black canvas dotted with stars.

"Yes, you are safe. It is me they want."

"Who's 'they'?" Cade tried to ask, but his small voice was drowned out by the great vacuum of space. The edge was only yards away. Panicking, he craned his neck to meet his gaze for the first time. "Optimus-!"

Horror seized his entire being. Looking down at him was not the Prime, but a grey, lifeless husk.

"Forgive me," it said.

Cade screamed.

He let go.

He fell onto the road, and instantly he was no longer affected by the powerful force. Still screaming, he watched helplessly as Optimus's body tumbled over the end of the world without him, then up into the air, floating farther and farther from Cade's reach, higher and higher into the heavens, till it was impossible to tell what was a star and what was Optimus Prime.

"You can't leave again! You promised…you promised!"

But it was too late.

He was alone.

(...And then he woke up. The end! lol)