Dr. Meredith Stinson was already a well known scientist, recognized for her accomplishments in many scientific fields—particularly in particle physics— when the lab accident occurred.All of her scientific knowledge and experience could not save her when multiple failsafe measures failed simultaneously and the particle emitter flooded the control room with tachyon particles. Dr. Stinson’s entire body was bombarded by these formerly theoretical particles, overwhelming her nerves and knocking her out cold.When she recovered, she found that she surprisingly suffered no adverse effects.

Shaken but returning to work, she began to notice an unusual increase in her efficiency.Tasks that would have taken hours were done in half the time, and she found herself unconsciously picking up speed as she moved about the lab. The consummate scientist, she ran a series of tests on herself and discovered that the cells within her body had been accelerated. Securing a wind tunnel within the facility for herself, she began to test the extent of her changes and found that she could move at superhuman speeds.

News of her findings quickly spread, resulting in the government recruiting her for a new initiative. Dr. Stinson was offered nigh-unlimited research funds in exchange for her joining the Freedom Four.That funding would mean she would have to take time away from the lab and her wife Dana at home, but it would also give her a chance to do a lot of good in the world. So, taking the name Tachyon, Dr. Meredith Stinson acted as both speedster and scientific advisor to the team. Over her many years of super-heroics alongside the Freedom Four, and later the Freedom Five,Tachyon made quite a name for herself as the fastest hero and the quickest thinker. She also cultivated a deep friendship with her teammate Ryan Frost, AKA the hero Absolute Zero. Later, she took on an intern named Devra Caspit, who had powers of her own.That intern in time became the hero Unity.

Recently, the Freedom Five fought alongside all of the heroes of Earth and beyond against a foe that threatened all reality: OblivAeon. Prior to that fight, Tachyon had sustained notable injuries in combat against Progeny, a scion of OblivAeon, and was still not fully recovered for the OblivAeon battle. Moving at high speeds was causing additional injury to herself, and she pushed herself beyond her limits to help save the day. As a result, she now must wear various stabilizing devices to monitor her speed and keep her body from tearing itself apart. Still, she uses her speed and her mind to stand in defense of the world against any who would threaten this world.