Shade actually kept a diary, but not a real one. After inheriting the previous detective's notebook, he spent five or six days a week writing useless lines such as "No clients today, savings decreased," or "Little Mia ate too much, consider asking Miss Goode for money."
Professor Drake, unlike Shade, had the good habit of recording his life every day. His diaries had been preserved quite well, including all the entries from before and after that adventure more than a decade ago. On the surface, the contents seemed perfectly ordinary, but Shade noticed that in the few days before the professor set out for "Lake of Cherub," he had complained in his diary that his eyes were somewhat red and swollen, and that he saw double images.
Perhaps ordinary people would consider that a minor issue, but to a Ring Arcanist like Shade, if someone involved in an abnormal incident developed eye problems during an investigation, there was a high chance that their whole body had problems.
As for the letters, before Professor Drake departed for Lake of Cherub, he had corresponded intensively with friends and academic colleagues from other places to discuss various matters. The letters themselves concerned trivial things such as publishing papers, invitations for academic visits, and asking whether they could recommend any students, but they made Shade suspect that if Professor Drake had encountered something strange before going to "Lake of Cherub," he might have written to other professors of history and folklore to ask about it.
Therefore, Shade could seek out Professor Drake's old acquaintances and ask whether the professor had raised any unusual questions more than a decade ago. He had this idea because, among that stack of yellowed old letters, he found a familiar name:
"Professor Tiris Manning of Tobesk?"
At the desk,