If You're the Real One, Then Who is My Husband?

'''She returned. Five years into the past. Having regressed, Rachel intends to first break off her engagement and then live a peaceful life, but... “How did you know that I am the Duke’s real son?” A single momentary mistake draws the attention of a terrifying man. * “Where are you going?” “I’m running away. I just ran into an assassin over there.” “…….” Strangely, he appeared only when Rachel was up to something suspicious. Perhaps it was because he was always looking at her with eyes full of suspicion. “Why have you come out alone again at this hour? It’s dangerous.” “……I have something to look for.” “……Come here. I’ll go with you.” Then, she suddenly realized something was odd...