Throughout Waterfell, Howard excels in sculpting complex, dynamic characters who evoke both the readers' sympathy as well as their annoyance. Unlike the bulk of teen beach-reads, Waterfell doesn't rely on vague stereotypes of "good" and "evil" to distinguish its characters. Rather, Nerissa, her adoptive brother Speio, bestie Jenna, and crush Lo all flaunt the nuances and imperfections of real-world human beings. Unlike real-world human beings, however, Nerissa and Lo seem incapable of disagreeing. And as adorable as their impossibly flawless romance might be, in the absence of conflict, Nerissa and Lo never get the chance to prove their sincerity. Waterfell unfurls at a somewhat lurching pace, the plot alternating between cutthroat under-the-sea espionage and lackadaisical high school melodrama. Although simply worded, Howard's prose flows effortlessly as water, rendering Waterfell a quick, compulsively readable thriller.