The Tongue Trade is science-fiction inflected noir, and your enjoyment will be closely linked to how much you buy the premise.  William Kirst is a translator in a world where languages have diverged so much that you need specialists to communicate between different professions (police, business, marketing, legal, IT, medicine, etc.). He's leaving dinner with a date when he witnesses the aftermath of a murder. Translating between another witness and a lawyer, he learns the shocking truth that his client was the killer.

Unfortunately an ironclad oath prevents translators from revealing what was said to third parties, even if it would be criminal evidence. Against his better judgement, Kirst is drawn into an investigation against a powerful businessman, one which involves a radioactive quarantine zone, Zeppelin shipping, beautiful dames, and murderous goons.

The best parts of this book are the epigraphs at the start of each chapter, a story of professional communication gone wildly awry. Secondarily is when the story leans on Kirst's skills to finding the meaning behind youth slang, criminal argot, and all sorts of weird jargon. The rest is good to adequate. The plot wraps up a bit too neatly and quickly for my tastes, without the layers of perverse sexual desire which make a true noir so dark.