When brilliant physicist Echo is sent back in time to correct a rogue time traveler's mistake, she must navigate the dangers of the past while confronting her own mysterious memories. As she fights to restore the original timeline, Echo finds herself drawn to Asher, a charming historian with secrets of his own. But with Caspian, a ruthless leader, hot on their heels, Echo and Asher must trust each other to survive – and uncover the truth about their tangled past.