Katja Laurence is a doctor at Central City General, but when the Particle Accelerator explodes, she becomes something more. She joins Team Flash after accidentally killing people that she was trying to save. She never felt like a part of the team, so when a mysterious time traveler tells her that she has a chance to become a hero, she jumps at the chance. Now Katja must join with a team of D-list heroes and criminals to fight their fate and become not just heroes, but Legends.