Sparked during The Great War, Trailfire was one of many children of Vos to find themselves caught between both the devastating civil war and their rivalry with Tarn. While she did well to keep her place, Trailfire dreamed of the grand era they might enter after the war finished, with herself high up in the spires of Vos, flying with the best of them.
Desiring freedom from the rigid system, Trailfire once resonated with the words of Megatron, seeing the war as a necessary evil at first. As the darkness grew to encompass all of Cybertron, however, she began to question the eventual destination of the war.
The destruction of Vos, and everything she had ever known, was more than she could take. While a small faction of fliers had escaped the devastating blast, none of her squadron or neighboring squadrons had. Those lower-ranking Seekers went off to side with the Autobots, while the higher ranking-- including their Air Commander, Starscream-- knelt to the Decepticons.
Thoroughly displaced and unwilling to yield to either side, Trailfire resigned herself to flee of her own accord, vowing to destroy either faction should she ever have the misfortune of coming across them again. Using her near-unmatched (and now exceedingly rare) agility and aerial prowess, Trailfire was able to secure a small supply of energon and a ship that could survive long-distance off-planet.
Although successful, her actions were not without consequence. She could not obtain enough energon alone, and in a desperate attempt to remain online as her energon depleted, Trailfire powered herself down. Her course was set for what was hopefully an energon-rich planet. Trailfire fell into a deep stasis, not to awaken for many, many years.
She would not reawaken until her ship malfunctioned and crashed landed on Earth. Trailfire took to searching for energon, finding much of it mined already. With a mix of hope and dread, Trailfire set out to discover just who-- or what-- was mining energon.
It would be with a heavy heart that she discovered the factions which destroyed their world.
Trailfire was sparked a into a Decepticon frame on a Decepticon-controlled planet some time after the defeat & exile of the Decepticon race. Infighting was terrible, and without a cohesive leader, Trailfire chose to leave the planet in the hopes of finding refuge elsewhere. Knowing she could never find sanctuary on an Autobot world, Trailfire sought other displaced bots through her ship's communications network, forming an unofficial psuedo-movement that refused to align with either side, despite how they were born.
At some point during her travels, finding herself low on Energon, a mysterious stranger picked up her distress signals. Claiming to know of an unaligned planet that both had energy and a habitable surface, Trailfire began following the tantalizing promises of this stranger. Dubbing himself Megatronus, Trailfire would follow his signal to a small blue-and-green organic world called Earth; a planet he had claimed ownership of.
As they spoke, Trailfire's feelings towards Megatronus became increasingly confusing, particularly because he would not reveal himself to her. All she knew was his voice and wise words... and surely that someone like him couldn't be lying.