I often see this question pop up in reader groups. If you're new to her work, I'd suggest starting with the first Veronica Speedwell mystery, 'A Curious Beginning'. It throws you right into the world of a fiercely independent lepidopterist in Victorian London who finds her life upended after her last relative dies. The dynamic between Veronica and the brooding natural historian Stoker is electric from the get-go—full of witty banter, reluctant partnership, and a slow-burn tension that really anchors the series. The plot is a fun mix of historical detail and adventurous mystery, but it’s the character voices that make it such a memorable entry point. You get a complete story while the groundwork is laid for their longer personal arcs.
Her stand-alone novel 'The Dark Enquiry' is another solid starting point, though it’s technically later in the Lady Julia Grey series. I mention it because it showcases her ability to write a complex, Gothic-tinged mystery within a single volume, featuring a married couple who investigate together. It gives you a feel for her richer, more atmospheric historical settings without the commitment of reading several books in order. That said, the chronological start of the Lady Julia series, 'Silent in the Grave', is wonderful if you’re in the mood for a slower, more atmospheric burn with a pronounced Gothic romance influence. The pacing is deliberate as it builds Julia’s world, so it depends on whether you want immediate action or a moodier immersion. Either way, you're getting a signature blend of sharp dialogue and intricate puzzles set against vividly drawn historical backdrops.