I'm not a Buffy follower, but I'm not having any trouble following your story so far.
“It wasn’t until that night that I realized just how wrong things were.” Marcus looked up, looking Lois directly in the eye. “That was the night Rachel came back.”
That's something that doesn't happen that often in Metropolis - unless cloning's involved.
![shock shock](/ubb/images/graemlins/default/shocker.gif)