When Abby goes missing and Emma realizes that she's the last one who's seen her, it triggers a torrent of memories -- about the fun they used to have together, and about how Emma ran away from their friendship because Abby got too embarassing to be with (with her Goth fantasies and other non-trendy stuff). As days turn to weeks, and the chances of finding Abby diminish, Emma comes to the realization that she's lost a real friend.
Moderately predictable, but satisfying story with an edge of suspense (about as much danger as Brit YA Lit ever seems to allow -- have you ever noticed that the kids in UK children's lit are on such tighter leashes than the Yanks?). Some nice unorthodox friendships (where things don't necessarily work out) and less unusual parents (who go rather abruptly from being unreasonable to being totally cool). A mixed bag, but not a wasted read.