This is the 4th book of a series where they all have the same premise, which could have gotten a bit tired, but it was redeemed by the author taking some chances. The heroines in the series are all basically hiding out in the Tantalus Club, a private gaming and dining establishment which is completely run by women. This particular heroine, Emily, is hiding because she witnessed a murder committed by a powerful man, who would have her killed or jailed if he found her. The author had her do some things that stepped outside normally acceptable historical romance conventions, and some people may find her behavior unlikeable, but I found it refreshing. She was a survivor.
The hero, Nathaniel, was also somewhat unconventional, which kept things interesting. The HEA was off the beaten track too, not what I expected. It was a bit poignant actually, they end up together of course, but all is not total sweetness and light.
My main quibble is with the title, first of all because it makes the book sound like it's going to be a light-hearted romp, when overall it's a pretty serious story; actually Emily's problems are dead serious. Secondly, the title was inappropriate because there is no handbook involved, and Emily is not in any way capable of "handling" Nathaniel. She's had to become devious in order to survive, but he's an ex-spy and even more devious.
So, I don't rate it as high as my favorite Enoch books, but well written, and I liked it better than many of her more recent works.