From the Goodreads synopsis, because it’s been a month since I read it, and the blurb is part of what drew me in:
Newly arrived in New Fiddleham, New England, 1892, and in need of a job, Abigail Rook meets R.F. Jackaby, an investigator of the unexplained with a keen eye for the extraordinary – including the ability to see supernatural beings. Abigail has a gift for noticing ordinary but important details, which makes her perfect for the position of Jackaby’s assistant. On her first day, Abigail finds herself in the midst of a thrilling case: A serial killer on the loose. The police are convinced it’s an ordinary villain, but Jackaby is certain it’s a nonhuman creature, whose existence the police – with the exception of a handsome young detective named Charlie Cane – deny.
Doctor Who meets Sherlock in William Ritter’s debut novel which features a detective of the paranormal as seen through the eyes of his adventurous and intelligent assissant in a tale brimming with cheeky humour and a dose of the macabre.
I can absolutely see why the publishers decided to mention both Doctor Who and Sherlock in an attempt to draw readers to this book, which I first saw mentioned by The Book Smugglers. The gorgeous cover and the interesting blurb made me curious, and I saved the book to read during October’s 24-hour Readathon. I’m glad I did. I’m assuming the Doctor Who comparisons come from the fact that we see the story through the eyes of a clever young woman, like so many of the Doctor’s companions through the years. Jackaby himself is clearly at least partly modelled on Benedict Cumberbatch’s Sherlock, both in looks and mannerisms. Sir Arthur Conan Doyle’s fictional detective is even name checked early in the book. Yet there is a supernatural twist to this Victorian mystery, involving a number of creatures from Gaelic mythology. There are ghosts, a man turned into a duck, a werewolf and some fairly gruesome murders.
Abigail Rook is a delightful narrator. Having run away from her family’s expectations to join an archaeological dig (and finding it rather dull), she ends up on a ship to America. Trying to find a job, so she doesn’t have to return home, she meets the eccentric and mysterious Jackaby, who’s looking for a new assistant. He’s not at all sure she is suited for the position, but after accompanying him to a crime scene and impressing him with her quick thinking and admirable common sense, a nice balance to his own off-beat thinking, he agrees to keep her on a trial basis.
Full review here.

This has been on my TBR list for a few months now. Bumping it up to the top! This sounds like it is definitely in my wheelhouse.
I really liked it. I hope he turns it into a series.
This is the Amazon deal of the day for Kindle. Just downloaded for $1.99! Great timing!
That is awesome. That is a lot less money than I paid for it. May buy one as a gift for my friend who also likes these sorts of books. Thanks for letting me know.
$1.99? I’m in! Thanks for the heads up :)