He had it all worked out. Rodimus had the perfect vision of how the reunion would pan out:
It would be on Earth. There is like a forest of those pink trees that Drift told him about. Pink petals cover the bodies of hundreds of slain Decepticons. Rodimus is standing in the middle of the corpse mountain, heavily panting. The last standing opponent is the terrifying Decepticon leader.
The leader charges with a furious roar. Rodimus raises his weapons, not fully sure whether he has enough strength left to finish this fearsome warrior. Then... a blade penetrates the Decepticon from behind. With a surprised look on his face, the Con falls over and reveals who is standing behind him.
It is Drift.
Rodimus and Drift look at each other, not sure what to say. They wish to embrace each other as spark-brothers, but so much time has passed and they are not sure, whether they can go back to their old ways...
Suddenly, Rodimus shoots! He hits the Con that had sneaked up and was about to kill Drift! Drift looks around in shock, and then realizes that he had just been saved from certain death. Drift stretches out his hand and Rodimus grabs it, finally reuniting with his best friend and most trusted advisor.
It's a touching scene. The pink petals keep gently floating to the ground, while Con blood leaks into the ground and while two noble warriors reignite their friendship. Really, it'd be just perfect.
That's the day-dream version. Rodimus had perfected it in his mind while listening to lectures by Ultra Magnus and grown pretty fond of it. Yeah, it wasn't very realistic, but that wasn't the point. Rodimus just missed Drift and wanted his friend back.
It would be different in reality, of course. It could happen that Drift would decide to come back, since the reason for his exile was bullshit anyway. Perhaps Drift would mingle in Cybertron bars and find out that Rodimus had come clean about Overlord. Drift would then know that he could come home now.
It'd go something like this:
They receive Drift's message and request for docking. A welcoming party lines up, with Rodimus at the front. When Drift walks out of the shuttle, Rodimus is fully prepared. He gives a speech about his own failings, how noble Drift was for taking the fall and letting the quest continue, and how disgraced Rodimus feels for letting this happen.
Drift is surprised and touched to see how Rodimus has changed. His old friends are there, eager to embrace him and to share stories of their adventures.
In the end, Rodimus humbly asks for forgiveness and whether Drift would like to be the second officer again, as he has proven his loyalty and selflessness and there was no doubt....
Was it even right? Rodimus never thought of this before, but Drift wouldn't have much choice in that situation. Everyone was always eager to latch on to his Decepticon past, and if Drift refused to accept the apology, he would become again the former-Decepticon-not-fully-Autobot who holds grudges and looks suspicious, and since the Con hates our captain, he is definitely is planning to betray us at the first chance he gets...
Alright, second try. Personal quarters, talk eye to eye.
Rodimus asks for forgiveness and whether Drift would like to be the second officer again, because frankly Rodimus needs someone as capable as Drift at his side. And Rodimus is sorry... for everything. He dumped everything on Drift - the responsibility and the blame - and never thought about anyone but himself.
This time Rodimus would listen to criticism. He needed to hear real advice, even if it meant getting called out and told off. Rodimus needed Drift, as and adviser and a friend.
Drift would slowly raise his hand and put it on Rodimus' shoulder. Drift would smile and say: "I'm with you till the end."
It wasn't a bad version. A realistic view of how things would go. But Rodimus couldn't help wondering whether he was wrong? Is this what Drift would do? Just accept things as he always did?
If he did not...
Rodimus staggers back, when Drift's fist connects with his face. The first instinct is to fight, but Rodimus stops himself and lowers his head. The punishment is deserved.
Drift has many things to say:
"Why did you let me down? Why couldn't you ever listen to me? Overlord could have stayed on Cybertron and spared us the deaths of our friends!"
Rodimus knows it.
"You made Overlord my responsibility. My restless nights of worry. What were you doing in the meantime? Doodling? Backflips? Pissing matches with Ultra Magnus?"
It was the truth.
"You exiled me - but even worse, risked your status as a captain just to "come clean". Played the hero! You are supposed to find the Knights of Cybertron... this was the only reason I followed you, after all."
Drift would storm out and leave Rodimus alone in the office. It would take time to earn his respect and trust. But Rodimus was willing to try, no matter how long it would take.
No, not like this. Drift cared about Rodimus beyond his function, beyond whatever Drift thought Rodimus was destined to do. They were friends and while the fallout was bad, it was not beyond salvaging.
Even this bitter scenario made Rodimus hopeful. At least it was a chance to make things right. Better to have Drift back, then wallow in uncertainty and go through hundreds of reunions in your head, not capable of picking a single one.
Maybe Rodimus was afraid. There was this recurring dream that Rodimus had. More like a nightmare.
Drift would come back and...
Rodimus would be distracted by something - busy talking with Ultra Magnus, checking schedules or stuck inside captain's quarters - and wouldn't notice in time Drift's arrival. All his friends would welcome Drift back, slap his shoulder and embrace him, and Rodimus would miss his moment. Drift would smile in earnest, forgive everyone who was quick to blame him for Overlord. Forgive even those, who hurled trash and insults at him after his exile.
But Drift wouldn't smile at Rodimus, he'd just look past him. When Rodimus would finally have the time to talk to Drift, the bot would just kindly evade the conversation, slip through his hands with a non-committing smile. There would no hatred or rage left in Drift, nor love or bitterness. Just an empty hole which words can't fill.
Sometimes redemption arcs don't work out. When a spark is extinguished, you can shake the corpse all you want, but dead bots don't forgive their killers. When a friendship is broken, even a reunion won't save you from being alone. Rodimus had fucked up one too many times. It was too late.
Perhaps it was for the best if Drift never returned, after all.