Fans know what to expect from Cooney (The Voice on the Radio, 1996, etc.): bullet-train pacing and entertaining prose. This accessible offering opens as Billy Williams, 11, accepts a package from a passerby and is blown up in a London tube station. The action is full steam ahead as the Williams family mourns and attempts to go on, except for Laura, 16, who embarks on an absorbing and obsessive journey to find her brother's killer. The novel isn't perfect: Laura's transformation from a self-involved ""ugly"" American abroad to vengeful paranoiac is fairly convincing, although readers may have trouble getting past their initial dislike of her and her self-satisfied oblivion. While most of the characters are as real as their grief--making human choices, and suffering the consequences--others simply fade out of the story, and the culprit is based more on a stereotype than on logic. If the novel requires a few big leaps of faith, readers will be glad they stayed with it, and will be caught up in exciting, compulsive reading.