The Pursuit of William Abbey by Claire North

First, let me say that this book covers a lot of ground both geographically and in genres. The story is both historical, mythical and supernatural. In the late 1800s, a young doctor witnesses the brutal killing of a black boy in South Africa and is cursed with the boy's spirit chasing him forever, killing anyone the doctor cares about. The second part of the curse turns William Abbey into a "truth-teller" allowing him to hear the truth from people which he is then compelled to share. Soon this ability makes him stand out to an organization called the Nineteen who recruit Abbey and others like him to spy for them. This takes the doctor to many locations all over the world and when he does try to escape them he flees not only his spirit shadow but also this blood-thirsty organization. He can never stop or settle down too long in any one place so his journey at times feels like a never-ending sea voyage with moments of panic or awe but mostly calm endless seas.