Mom still knew nothing.
The clock reached 8:59.
Dad looked toward the front door.
Then he looked at Mom.
And exactly at nine o’clock, the doorbell rang.
Mom smiled and started to stand up.
But Dad grabbed her hand.
“Margaret… please sit down before you open that door. Because the person standing outside has come here from our past.”
Mom’s smile disappeared instantly.
And when someone knocked on the door for the second time, Dad finally reached for that old envelope… 
Full story in comments 
The second knock sounded louder than the first.
Mom looked at Dad, confused.
“William, who is that?”
Dad didn’t answer immediately.
Instead, he picked up the envelope and placed it in her hands.
“Read the name on the back.”
Mom turned it over.
Her face changed.
I leaned closer, but before I could see anything, Dad whispered:
“Her name is Catherine.”
Mom stared at him.
