Set in Sydney, this light-hearted science fiction thriller proposes that visitors from another world are living among us, making sure we don't learn how to use wormholes in space-time. The visitors, calling themselves Callum and Jacob, come from a red dwarf star system in Libra, so our sun feels dangerously hot and in sunny Sydney they stay indoors, wrap up outside, look pale and move best at night. Unavoidably this leads fans of the vampire fiction craze to zero in on them as probably vampires.

HAVE WORMHOLE, WILL TRAVEL - the title is a homage to early book Have Spacesuit, Will Travel - would make us feel quite sympathetic towards these off-planet folks, if they weren't so busy discrediting cold-fusion research and interfering in the lives of string-theory professors. Callum and Jacob see Earth's dependence on fossil fuels as dangerous to their home world, which contains such materials but does not employ them. In order to stop Earth people heading their way they need to stop us travelling faster than light. Local girls Mandy and Sabrina, meanwhile, are busy trying to track down the suspected vampires, using smartphones, photo-recognition programs and conversation in bars. Partly because they think the guys are hot.

A physics professor, Dr. Sam Sheppard, is quietly working on lines which look likely to succeed in making usable wormholes, and Callum and Jacob are ordered to discredit his work. We'd like Sam better if he wasn't so delightedly certain that his breakthrough will bring him fame, fortune and work at his pick of locations; he can't stop bragging to his girlfriend, who doesn't understand and thinks he's nuts, or hinting to his grad students class. Callum's off- planet boss charmingly refers to Earth people as "mind- numbingly stupid, incredibly xenophobic and violent beings" so you can see why they don't want us coming any closer. If the visitors can't sort out the situation, all Earth will have to be wiped clean of people. But the two guys have been here long enough that they've got to like us.

Sydney is described as a very diverse city, where the vampires - sorry, visitors - see all races living in harmony. They remark that in a mere hundred years humans have gone from the Wright brothers to sending a shuttle to repair a satellite. Who knows where we'll go next? Tony McFadden is clearly having a lot of fun with this tale and if off-worlders do HAVE WORMHOLE, WILL TRAVEL, I'd love to meet them.