That evening, I reviewed the rest of the footage. My hands shook.

After knocking, she pulled a small silver key from her pocket. She held it to the lock — not turning it, just pressing it there — before leaving.

The next morning, desperate, I searched Liam’s nightstand. Inside was a worn notebook. One page read:

“Mom still checks the doors every night. Says she hears something — but I don’t. She asked me not to worry. I think she’s hiding something.”

When Liam saw what I’d found, he broke down.

He told me that after his father died years ago, Margaret developed severe insomnia and anxiety. She became obsessed with locking doors, convinced someone was trying to get in.

“Lately,” Liam whispered, “she’s been saying things like… ‘I have to protect Liam from her.’”

A cold wave washed over me.

“From me?” I choked out.

He nodded, ashamed.