Caitlin Snow and Barry Allen both have traumatic pasts involving Eobard Thawne, or as they know him, Dr. Harrison Wells. He killed Barry's mother, and was the cause of Caitlin's father's death. Will their shared experiences bring them closer together or tear them apart? The night Eobard Thawne staged the car crash that would kill Harrison Wells, a young girl unexpectedly entered the scene. Eleven year old Caitlin Snow was in the oncoming car and was injured during the crash while her father, the driver, was killed immediately upon impact. Thawne couldn't leave the girl to fend for herself and took her under his wing for the next fifteen years. It wouldn't be so bad to have an apprentice right? Someone to look after. But what happens when she befriends his greatest enemy, the Flash. What happens when she falls in love with Barry Allen?

Team Flash is still recovering from the emotional and physical aftershock of the black hole that tore apart their team and Central City. Little do they know, they have only just begun to experience the full effects of the catastrophe. New people and new feelings will send Team Flash on a roller coaster of coming together and falling apart, all in the hunt for a way to stop their new big bad. Will Caitlin be able to move on with her life and her relationship with Barry with the image of Harrison Wells haunting her? How will Barry react when a new has-been speedster threatens his position among the team, his friends, and Caitlin? Will Barry's need to save those he loves drive them away from him when he's faced with a new foe? Will the team's trust issues start to apply to each other when confronted with familiar faces and a more ominous speedster...Zoom?