When the Argonauts—so the story goes—sailed toward the Black Sea, they had to deal with giants, harpies and murderous women. When, in April 2018, Jens Mühling, a German journalist and a writer, arrives on the Black Sea coast during the early stages of the journey he so vividly describes in “Troubled Water,” he ends up drinking—a river of alcohol flows through this book—with a Russian (Oleg, naturally) and a Crimean Tatar (Elvis, naturally) in the courtyard of a rundown fishing cooperative on the western tip of Russia’s Taman Peninsula. A mile away, a newly built bridge awaits its formal opening. It connects the peninsula with Russian-occupied Crimea: “We screwed up our eyes, shelled Black Sea shrimps, and observed the world’s largest country in the act of growing.”