An Hour Unspent — Roseanna M. White

Once London's top thief, Barclay Pearce has turned his back on his life of crime and now uses his skills for a nation at war. But not until he rescues a clockmaker's daughter from a mugging does he begin to wonder what his future might hold.

Evelina Manning has constantly fought for independence, but she certainly never meant for it to inspire her fiancé to end the engagement and enlist in the army. When the intriguing man who saved her returns to the Manning residence to study clockwork repair with her father, she can't help being interested. But she soon learns that nothing with Barclay Pearce is as simple as it seems.

As 1915 England plunges ever deeper into war, the work of an ingenious clockmaker may give England an unbeatable military edge--and Germany realizes it as well. Evelina's father soon finds his whole family in danger--and it may just take a reformed thief to steal the time they need to escape.