The Iron Wyrm Affair, The Red Plague Affair, and The Ripper Affair by Lilith Saintcrow (323, 320, and 386 pages. 1029 total)
It might not be the most accurate description in the world, but I think I am going to call this a reimagined Sherlock Holmes. It follows the same basic principles; a mentath (beyond genius), Mr. Clare is led and guarded by a sorcerer Ms. Bannon and together they solve crimes for the Crown. Mr. Clare follows the same tendencies as Sherlock. He regularly sits in a chair puffing on a pipe in thought, is prone to wild experiments when between missions, and exhibits the same observation to detail that reveals everything about a person. Ms. Bannon, while a sorcerer, is also quite clever, but serves more as a grounding rod for Clare much like Watson. She also frequently finds herself in a bit of trouble that relies on more than her efforts to escape. But on the other hand, there are also mythical creatures such as wyrms, and gryphons.
The Bannon and Clare series was well worth the read and I fully enjoyed them. If you have read Shadows Over Baker Street and enjoyed it or other Sherlock adaptations I would recommend giving this a try. It also has some steampunk themes, for those that are interested.