This is something I made for a friend for her OC
Knock Out grimaced as he stared out the medical bay window, a fist under his chin. No matter how far the ship had moved, only vasts amount of space would stare back at him. From time to time, a planet would come into view but it'd be gone before he could even blink. Of course, if the planet happened to be rich with energon, Megatron would order a retrieval. Unfortunately those didn't last very long. Maybe a couple hours at the most.
In truth, Knock Out liked it when the ship stopped to retrieve energon. It gave him a chance to search for his lost love, whom he hadn't seen in many cycles. The last time he had seen his love was when they were still on Cybertron, before the war got at it's worse. At the time, Knock Out was considering becoming a neutral in the war and starting a clinic with his love. However, before that could happen, his love told him that they had to leave.
The mech was never told why his love had to leave, but he knew it was unwillingly. At first he had assumed that his loves' family had pressured them into being an Autobot, like how his had pressured him into being a Decepticon. Relationships between fractions solemnly ever worked out; especially if an apposing Decepticon found out. They'd consider the relationship a betrayal and order the Autobot's death, as well as the betrayer. If another Autobot found out, they'd likely think the Decepticon was using the other to get what they want and capture them for interrogation.
After a while, Knock Out came to the conclusion that wasn't the reason. Though keeping each other safe is exactly what an Autobot would do, he knew something else was responsible for his love leaving. Just what that reason was he didn't know. Not yet at least. He planned to find out, even if it took him a few hundred years.
Unfortunately, the now Decepticon doctor, had absolutely no luck in finding any traces of lost love. As the years past he grew more and more angry about it, having convinced himself that someone was keeping his love away from him. It was either that or they were stranded on a planet with no way to call for help. What other reasons could there be? He knew that his love would purposely avoid him and leave him to worry like this. They weren't nearly deceptive enough for something like that. They had to either be held captive or stranded.
That was why Knock Out loved stopping at planets so much. Although the chances of finding his love were slim, he never gave up hope. When he couldn't pick up the frequency single, he reasoned that they were just too far away. That was partly why he agreed to be part of Megatron's crew. Aside fulfilling his sadistic tendencies, which he had gained over the many years of acting as a Decepticon, he got to search the galaxy for you.
After a while, Knock Out's grimace became a thoughtful frown. That was the fourth planet the ship had past in the last several hours. He didn't recognize a single one either. In fact, this whole vector of space looked new to him. Were they in a new solar system already? Hmm, perhaps the doctor hadn't noticed because all the planets they've past so far seemed uninhabited and not very interesting. Well, aside from that giant red planet the ship just past. It's too bad that a planet that size would crush beings like him. Well, at least he knew his love wouldn't be there.
Suddenly and without warning, Knock Out felt his spark pound in his chest. His face lit up with anticipation and he felt his body give small shivers. He... his love... he... he could feel them... he was getting closer to where they were! He was so close to finding them, and so close to being with them again.
Quickly turning from the window, Knock Out strut to the side of the room, where his work bench was. There was so much work he had to do before seeing you again. He had to make himself look presentable. After all, he wouldn't want to make the wrong first impression after so many years. He only hoped you had no idea he joined the Decepticons in the end.