The bell after closing

An original fiction passage set in the nineteenth century.

Clara had helped in the apothecary’s shop for so long that she could recognise each drawer by its scrape and each bottle by the shape of its shadow. At closing time, she swept the same strip of floor, lowered the lamp and watched her father turn the key. That evening, when he had gone upstairs, the bell above the door gave one clear note.

Clara raised the lamp again. The key remained in the lock, the windows were fastened and the shop was empty. Only a brass weight on the counter seemed disturbed: it was turning slowly on its edge. She touched it, and it fell flat.

“A mouse,” her father called when she told him.

Clara looked towards the door. Mice did not ring bells. She had almost lowered the lamp when, behind the neat row of bottles, glass clicked softly against glass.

Analyse how the writer uses language and structure to create uncertainty in an otherwise familiar setting. Support your answer with references to the passage.