Only the outline remained where dust had not settled.

We found the second detector in the kitchen, unplugged and missing its batteries, sitting uselessly on the counter.

Miles examined it carefully and said, “This was not accidental, someone removed the power deliberately.”

In the trash, he found a receipt from a hardware store listing a flue vent kit, duct sealant, and batteries.

The realization hit hard.

Someone had purchased batteries.

And yet none were in the detectors.

PART 3

By the third day, exhaustion made everything feel unreal, as if I were watching events unfold through thick glass instead of living them directly.

My parents remained unconscious, and the doctors spoke cautiously about oxygen deprivation and neurological impact, using clinical language that felt detached from the emotional weight of the situation.

Brittany stayed nearby, hovering with forced concern, bringing coffee that was always wrong and asking repeatedly if the cause had been confirmed.

The detective returned with more questions, this time focusing on finances and legal matters, which made Brittany suddenly more animated as she explained that our parents owned their home outright.

That detail landed heavily in my mind.

That night, Miles accessed the smart thermostat system and found that several logs had been deleted.

Deleted.

Not missing.

Not corrupted.

Intentionally removed.

We returned to the house again, and this time Miles inspected the furnace vent closely, pointing out fresh scratches around the screws.

“This was loosened recently,” he said, his voice steady but tense.

In the kitchen drawer, we found the missing hallway detector hidden among random items, completely stripped of batteries.

Back at the hospital, I searched through my mother’s belongings and found a torn note in her handwriting that read only, “Do not trust.”

The unfinished warning sent a chill through me.

Miles accessed the doorbell camera system and discovered gaps in the footage, but after attempting recovery, one clip reappeared.

It showed a hooded figure entering the garage late at night.

The image was grainy, but the movement, the posture, the unmistakable urgency in the way the person walked made my chest tighten.

I knew that walk.

I had grown up following it.

PART 4

I did not confront Brittany immediately, because the idea of accusing my own sister felt like crossing a line that could never be undone.