Irish author Kate Thompson gets her transformational trilogy off to a shivery start in Switchers.

Tess is a Switcher, able to change into any animal she chooses. She discovered this ability at a young age, but she has kept it a secret, believing herself to be the only one. Tess is an only child, and while she and her parents are close, she can't tell them about this.

Her father's job has moved her family all around Ireland, so Tess doesn't have any friends. By the time they move to Dublin when Tess is 13, she has become practiced at remaining aloof. But she can't seem to avoid Kevin, the boy who persistently meets her when she gets off the bus.

Then she learns that Kevin is a Switcher, too, and he needs her help to fight the cause of the prolonged winter in the Northern Hemisphere. Tess doesn't believe him at first, but when he proves that he's a Switcher, she agrees, if reluctantly, to follow him. Their animal odyssey leads them to Lizzie, an elderly solitary woman who was a Switcher as a child. Lizzie can't change into animals any longer, however; Tess learns that Switchers have to choose whether to be human or animal on their 15th birthdays. This limitation underlies Kevin's urgency; his 15th birthday is approaching, and time is running out.

Lizzie tells them that oil drilling has awakened the krools, huge cold jellyfish-like things which slumber in the ice until awakened, then consume everything in their paths. As they progress south, they bring snow and cold weather with them. Already, UN forces are searching for the cause of the bizarre weather and an explanation for the disappearance of people in the Arctic, but none of them have identified the krools. Tess and Kevin are convinced enough to go try.

The two travel north, Switching from form to form until they find themselves confronting the terrible krools. Although they can't communicate with the UN forces, they figure out a way to use the "if you can't identify it, kill it" mentality against the krools, but with tragic results.

Thompson's plot is completely engrossing, and the characters of Tess and Kevin are very well drawn and sympathetic. Especially intriguing is the time the two spend as rats; here, Thompson paints a brief but deft portrait of rat society. Some of the details are a bit questionable: the Switchers' clothes change with them, and while that is certainly convenient for the characters, it strikes the reader as implausible. The age limitation adds to the suspense of the plot, but it seems a bit contrived in that it is clearly a plot device. Still, it's easy enough to suspend one's disbelief and overlook these minor flaws.

Know any hungry readers who have already finished the latest Harry Potter? Tell them to try Switchers.

[ by Donna Scanlon ]