Skies of Steel by Zoe Archer

In the world of The Ether Chronicles, the Mechanical War rages on, and appearances are almost always deceiving . . .

The prim professor

Daphne Carlisle may be a scholar, but she's far more comfort-able out in the field than lost in a stack of books. Still, when her parents are kidnapped by a notorious warlord, she knows she'll need more than quick thinking if she is to reach them in time. Daphne's only hope for getting across enemy territory is an airship powered and navigated by Mikhail Denisov, a rogue Man O' War who is as seductive as he is untrustworthy.

The jaded mercenary

Mikhail will do anything for the right price, and he's certain he has this mission—and Daphne—figured out: a simple job and a beautiful but sheltered Englishwoman. But as they traverse the skies above the Mediterranean and Arabia, Mikhail learns the fight ahead is anything but simple, and his lovely passenger is not entirely what she seems. The only thing Mikhail is certain of is their shared desire—both unexpected and dangerous.