The blurred order

An original fiction passage set in the nineteenth century.

Clara wiped the brass clock and turned its tag towards the light. The street written there matched the address beside a damaged entry in Mr Bell’s order book, and she pencilled ‘Mrs Linton’ above the stain. Beneath it, another entry named a Mrs Linden at the same street. Clara left the clock on the inner shelf and sent the errand boy to ask at the address before wrapping it for delivery.

Give one inference about what Clara is still unsure about and support it with one detail from the passage.