Nyx
The missing stroke was a join.
Nyx had spent two days treating it as the end of a number.
She placed the older index beside the enlarged copy and turned the page until the lines ran in the same direction.
There.
The curve continued into the next mark.
She turned the enlarged tracing back the way she had drawn it yesterday.
Wrong.
Not badly copied. Badly read.
The same surviving stroke became part of a different mark when she stopped assuming it was a number. The old index used joins where the newer working copy used separate entries.
Nyx slid yesterday's notes aside. Several careful comparisons had depended on the first mistake.
She did not tear them up. Anyone following the work later would need to know why she had changed direction.
The clerk cleared his throat behind her. She had been standing in the path of the packet he was trying to pass to the record keeper.
She moved without taking her eyes off the join.
