You'll find the chronological order of Joy Ellis's Rowan and Jackman books [[Joy Ellis's DI Rowan Jackman and DS Maria Evans Books in Chronological Order|here]].
The DI Nikki Galena series is based on the Lincolnshire fens and they're atmospheric. The body count is high - too high for me on occasions. If you're listening to the audio version (in November 2023 most of the series is available free with your membership) beware of the narration. It annoyed the hell out of me.
{{amazonurl|isbn=1789312787|title=Mask Wars / Crime on the Fens}} (2010)