It led not directly outside, but into a narrow parts-storage room first.
Beyond the storage room was another steel door opening into the back alley.
The inner door had an old latch that clicked when pressure came from the storage side.
Wind outside could move the outer door.
It could shake the frame.
It could whistle through the weather stripping.
But the sound Nora had just heard had come from the inner latch.
She closed the sketchbook.
The noise stopped.
She waited.
Five seconds.
Ten.
The back door moved again.
Barely.
Not enough for anyone else to turn.
Nora stood.
She did not rush.
That was another habit Lucas had noticed.
When uncertain, Nora moved more slowly, not faster.
She crossed the garage and touched Lucas lightly on the sleeve.
He looked down.
“What’s up?”
She leaned closer.
Her voice was almost a whisper.
“Don’t open that door.”
Lucas frowned.
“What?”
Nora looked toward the rear of the garage.
“It’s not the wind.”