A Matter of Circumstance and Celludrones — Claire Robyns

Greyston Adair is a Scotttish rogue, a blackguard and a smuggler, although British Customs will have to catch him red-handed to prove the latter. Fortunately, the dirigibles they float around in have never been able to get near his air dust.
Lady Lily d'Bulier is prim, proper, and prefers to think of herself as pragmatic rather than timid. And avoiding life-threatening situations at all costs is just plain practical. But everything changes when Lord Adair tracks her down in London; searching for answers he seems to think she has.

Hell is rising, One Demon at a Time...

With Lady Ostrich hunting them, and the mystery of how their lives tie back to Cragloden Castle and the powerful McAllister clan, Lily has no option but to throw propriety to the wind and run off with Greyston to Scotland, away from the immediate danger and toward possible answers.

The Complete Dark Matters Quartet:
1. A Matter of Circumstance and Celludrones
2. A Matter of Propriety and Parasites
3. A Matter of Desire and Dirigibles
4. A Matter of Arrogance and Apocalypses