Age of Steam, book 2: Tin Swift
Devon Monk2012

Life on the frontier is full of deceit and danger, but bounty hunter Cedar Hunt is a man whose word is his bond. Cursed with becoming a beast every full moon, Cedar once believed his destiny was to be alone. But now, Cedar finds himself saddled with a group of refugees, including the brother he once thought lost.

Keeping his companions alive is proving to be no easy task, in part because of the promise he made to the unpredictable Madder brothers--three miners who know the secret mechanisms of the Strange. To fulfill his pledge, Cedar must hunt a powerful weapon known as the Holder--a search that takes him deep into the savage underbelly of the young country and high into the killing glim-field skies defended by desperate men and deadly ships.

But the battles he faces are just a glimmer of a growing war stirring the country. To keep his word Cedar must navigate betrayal, lies, and treacherous alliances, risking everything to save the lives of those he has come to hold dear...