Shard actually keeps a diary, but he doesn't write a real diary. Instead, after inheriting the detective's diary from the previous generation, he fills it with useless sentences like "No clients today, savings decreased," or "Mia ate too much, consider asking Miss Gawder for money," five or six days a week.
Unlike Shard, Professor Drake has the good habit of recording his daily life. His diary is well-preserved, and entries from before and after an adventure over a decade ago are all there. Although at first glance the diary's content seems very normal, Shard discovered that a few days before the professor set out for Lake Cherub, he complained in the diary about his eyes being somewhat red and swollen, and seeing double.
Perhaps, to ordinary people, this would seem like a minor issue. But for a Circle Sorcerer like Shard, if anyone involved in an abnormal case has eye problems, it generally indicates that the individual has other issues as well.
