Yes I get it he's smart and he knows stuff but he's also an unbearable supercilious ass, so much so that I really didn't understand at the end that the heroine stayed anywhere near him. And she was way too innocent for her back story.
The story is set in 1882 and March Middleton comes to the door of Sidney Grice's house to stay there as his ward (now yes, she has to stay until she's of age but I then started the series that follows this and she's still in that house having stayed there). When she was a little younger she was with her father in India and there are suggestions that a love affair went horribly wrong (the temptation to capitalise the H and W there were great). She's smart but Sidney is smarter and he never explains himself or tells people why his conclusions are right, which puts March in danger more than once. The crime is twisty and messy and the outcome features some deus ex machina. I was left feeling unsatisfied and wanting more.