Elena, heroine of Kelley Armstrong"s impressive debut thriller Bitten, never planned that a casual sexual encounter would transform her into a werewolf. Neither did Clay, her lover and one of the leaders of the exclusive werewolf clique known as the Pack; women do not generally change or survive if they do. Elena"s considerable reservations about her new life come to a head and she walks out on the Pack to return to something like normality, finding herself a boyfriend who turns a blind eye to her occasional disappearances in the middle of the night. She may have done with the infighting of werewolves, but they have not done with her; her former family call her back when they find themselves under threat from those they have excluded and dominated. Kelley Armstrong is very good on the sheer exhilaration of shape-changing, of running on four feet through forests, suburban greenery and urban back alleys; if there is a weakness here, it is that Elena"s relationship with the taciturn, untrustworthy Clay is sometimes a little too conventionally romantic--but the dark poetry of the best of the book overcomes this entirely. --Roz Kaveney