Bumblebee promised to come back, right after the war, he’d come back and they’d be the other and hang out again. He didn’t know at the time what his feelings were or how deep they ran. But he did know how much he cared for and wanted to see her again. It took a long time defeating the decepticons on Earth. But the autobots eventually do, after vorns of nonstop war, it was over. They could go home peacefully. Before they do though, Bumblebee tells them he has to take a trip up to California. The autobots are skeptical but allow him as long as he isn’t caught.
And so bumblebee does, buzzing with excitement to see Charlie again. He arrives at their neighborhood in front of her house—and a different family is living there. That’s odd. Strange. Perhaps they moved, his mind supplied. He sits there in his altmode, thinking about what to do next—until he saw an elderly man with an Afro. It was Memo!
Bumblebee is still glad to see him and transform and the two talk alone. He doesn’t understand how his hair turned gray or his soft human skin sagged with wrinkles. Memo is glad to see him until Bumblebee asks about Charlie.
No one could hear his spark shatter as he informs the bot she’s dead. That humans age much quicker than cybertronians and live much shorter than they do. He was too late. Three years too late. All that he wanted to say, all that he wanted to with Charlie went down the drain at that moment. His girl was gone.
Memo gave him the directions to her gave and he went there. A small tombstone laid there. She was unmarried with no children, buried beside her mother and father. He sat in his bot-mode, playing the Smiths on his radio as he mourned. She was truly gone.
When Bumblebee arrived back to the base he was quiet. His friends comrades asked what was wrong but he shut them all down. They arrived back at Cybertron but his mind was still on Earth where Charlie laid. Vorns would pass and the name of Charlie Watson would be forgotten. Lifetimes would come and go but on Cybertron, they remained barely aged. The only one to remember the music-loving mechanic would be the only one left who loved her: Bumblebee