Dropped at her aunt and uncle's crowded house in LeHillier, Minn., so that her divorced parents can do research together in Egypt on Nefertiti, 16-year-old Sadie's summer starts "with a bang," literally, and veers off into unexpected and even dangerous terrain. Writing from Sadie's point of view, using an authentic adolescent voice with an observant sense of humor, Davis creates an engaging, increasingly gritty (also brutal) bike-centric mystery (and romance). Led by Allie, aka AllieCat, Sadie's elusive new friend, a convict's daughter who is tough and fast, "always land[ing] rubber side down," and joined by Joe, sax-playing, cigarette-smoking and sad, she trains hard for a Fourth of July mountain-bike race (Sadie's first) at Mount Kato, in the scenic Minnesota River Valley. Until... July 1st, the day the kids find Father Malcolm, "his body beaten to a barely breathing, bloody pulp in the woods," and Allie goes into hiding. Despite some weaknesses, including poorly integrated gay content and an occasional tendency toward melodrama, the story is ultimately a celebration of biking and perseverance—a suspenseful ride. (Fiction. 14 & up)