The islands of Caldera are a shining jewel in a rather bleak world. A terrible calamity in the past had blanketed much of the world with a toxic "fug". Those who survived were forced to take to the mountains and the skies in wondrous airships. Life has since been a struggle, with only the most ruthless and crafty able to survive. To spare themselves the same fate, the Calderans erected a battery of guns to fend off the airships of the mainland. They isolated themselves from the madness of the world, choosing instead to focus on the pursuits of art and creativity.

In a world where arcane contraptions are capable of just about anything, running an antique shop is a dangerous business. No one knows that better than the Masker family. Strict rules and cutthroat competitors have pushed them to the limit. They need to make a big sale soon or they just might go under.

Imperial law enforcer Amaranthe Lokdon is good at her job: She can deter thieves and pacify thugs, if not with a blade, then by toppling an eight-foot pile of coffee canisters onto their heads. But when ravaged bodies show up on the waterfront, an arson covers up human sacrifices, and a powerful business coalition plots to kill the emperor, she feels a tad overwhelmed. Worse, Sicarius, the empire's most notorious assassin, is in town. He's tied in with the chaos somehow, but Amaranthe would be a fool to cross his path. Unfortunately, her superiors order her to hunt him down.

She’s happy renovating homes and occasionally thumping bad guys until she learns of a mysterious artifact hidden under the house she’s working on. Everybody from humans to orcs to werewolves wants it, and they’re willing to kill to get it. Things go from bad to worse when someone frames her for murder.

The Northern Alliance and its southern neighbor, Tressor, have been at war for generations. Almost since the war began an assassin has stalked the northern lands, quickly becoming a legend among the people for both its skill and its elusiveness.