Byder discovers the location of Ethaniels brother, Thorber, and Ethaniel goes to the airport to meet up with him. He arrives at the same time as Myroc, a bounty hunter hired by Banning to find Isaac Lobel. Isaac has a computer disc full of information about Banning's contacts and is going to sell it to Thorber. Myroc manages to capture Ethaniel and tells Thorber he will trade his brother for the disc. Laura, Thorber and Isaac join together to try and find Ethaniel and Myroc while Byder gets left with the job of looking after Emil, Isaac's brat of a son.

Ethaniel goes to meet Thorber alone. He returns with a high fever and is almost uncontrollable. Thorber realizes that he is not ill but is reverting back to his true Therian state and if he does that the atmosphere on Earth will kill him! Thorber takes him and Laura to a friend of his, Dr Tremblay, who may be able to help. While the doctor tries to keep Ethaniel alive Laura and Thorber follow the only clue they have, a matchbook and a name written on it. To save Ethaniel from the virus that is causing his change they need to find out who infected him in the first place, and do it in the next 24 hours.

While retrieving an object from a plane that crashed into a lake a female diver, Robin Morley, is lost as a tremor strikes. The plane belonged to one of Banning's corporations and Byder tells Ethaniel that there must be something important on board if he wants it back. Ethaniel and Laura head of to the lake to help look for Robin and to find out what was onboard the plane that Banning is so eager to recover.