THE BOAT CARRYING Zula, Jones, and Jones’s crew retraced the course taken earlier up the strait between Xiamen and Gulangyu. But just as they were clearing the northern end of the battery of passenger ferry terminals, the skipper cut the throttle and began to steer a course toward shore, aiming for a dark patch along the waterfront. As they drew in closer, ambient light from the buildings of downtown made it possible to see a few mean little piers hosting a motley assortment of smaller craft. Nevertheless, they were sturdy enough to support vehicles. A taxi was waiting on one of them. Leaning against it, a dark human form suspended between the bluish pane of a phone screen and the bobbing red star of a cigarette.