Lena Oxton (call sign: "Tracer") was the youngest person ever inducted into Overwatch's experimental flight program. Known for her fearless piloting skills, she was handpicked to test the prototype of a teleporting fighter, the Slipstream. But during its first flight, the aircraft's teleportation matrix malfunctioned, and it disappeared. Lena was presumed dead.

She reappeared months later, but her ordeal had greatly changed her: her molecules had been desynchronized from the flow of time. Suffering from "chronal disassociation," she was a living ghost, disappearing for hours and days at a time. Even for the brief moments she was present, she was unable to maintain physical form.

Overwatch's doctors and scientists were stumped, and Tracer's case seemed hopeless until Winston designed the chronal accelerator, a device capable of keeping Tracer anchored in the present. In addition, it gave Tracer the ability to control her own time, allowing her to speed it up and slow it down at will. With her newfound skills, she became one of Overwatch's most effective agents.

Tracer’s first mission took place in London, where she and her team successfully halted the Null Sector forces involved in the King’s Row uprising. It was the start of a stellar career: she would go on to help apprehend a valuable contact of Talon, Maximilien, in Havana. With the lead Maximilien had given them, Tracer’s strike team then put Talon’s leader, Doomfist, behind bars.

Following the disbandment of Overwatch, Tracer was dissatisfied with her quiet life, of replacing heroism with a desk job in the Royal Air Force. Shortly after leaving the military, an encounter with a like-minded omnic named Iggy led Tracer to the Underworld, where her eyes were opened to the harsh conditions the omnic population of London resided in. Assisting in repairs on the Underworld's Grid earned her an audience with the leader of the Shambali, Tekhartha Mondatta, though disaster was soon to follow.

Tensions between humans and omnics boiled over when Widowmaker’s crosshairs fell on Mondatta. Though Tracer was present at the event and even fought the sniper, she was unsuccessful in thwarting the assassination. The response was explosive and immediate—Mondatta’s message of peace drowned out in a sea of pain and stolen hope. When an omnic with possible ties to Null Sector stepped forward to rally the omnics of the Underworld in a full-blown revolution against humans, it was only through the combined efforts of Tracer, Winston, and Iggy that no one else was hurt.

Though she was grievously wounded in the process, Tracer can always be counted on to bounce back. With the help of Winston and her partner, Emily, Tracer made a full recovery, rejoining Winston and answering his Overwatch recall broadcast. Though she failed to stop Widowmaker in London, she thwarted the sniper in reclaiming Doomfist’s gauntlet in New York. And in Paris, Tracer was there to repel Null Sector, helping the newly re-formed Overwatch put a stop to any threat to peace.

With her irrepressible energy and boundless idealism, Tracer inspires her team—and all who know her—to fight for a better future.