This is not showing as part of a series, however it is the 2nd book in DeHart's "Ladies' Amateur Sleuth Society". There are four women involved in the Sherlock Holmes type society starting with Amelia, next is Meg in this book, and third is Willow. I do not see a book yet for the fourth character Charlotte.
When wildly independent Meg Piddington finds herself locked in her father's chocolate factory after hours with a most disarmingly attractive gentleman, she doesn't realize that she is his alibi-proof that Gareth Mandeville did not commit a dastardly crime. But admitting as much would destroy her reputation, which gallant Gareth refuses to do. Besides, he believes even prison would be preferable to marriage, which is what their revelation would certainly demand!
At last, here's the perfect opportunity for Meg to don her sleuthing hat to get to the root of the secretive stranger's troubles! Besides, the man sends oh-so-pleasant shivers coursing through her body. And though heaven may well await in Gareth's embrace, danger may dwell there also . . . if the determined lady embarks on a grand mission to win his love.