What do we want from tie-book? Solid characterization, that the characters sound like the original we know and love. Pack Animals does this and is entertaining too. The plot is a little foggy in places but the author doesn't shy away from what makes Torchwood fun and attractive. Namely, Jack being Jack, competent Gwen, amusing Rhys and putting forward Cardiff and making it real and interesting. A good tie in reads like an episode without the special effects that the production couldn't have afforded anyway. This one makes the cut.