Benny didn’t mean to travel in time, but he finds himself catapulted into Ancient Rome, where he splashes down in the middle of a mock sea battle.
He shouldn’t have tried to return the device he found to Zeff, the strange girl who landed in his back garden. Especially as, now he’s in the past, he discovers that Zeff is far from being in control of her own camper van-shaped inter-dimensional vehicle, the Windbird.
In Rome, Benny and Zeff befriend Ancient British warrior princess Gwyn and her faithful companion Cadmon, and encounter an array of historical and imaginary characters, including beasts, both natural and robiotic.
Together they come into conflict with the terrifying space criminal the Beastworker, time-locked in Rome for her crimes. Her alloid army is nearly ready, and the Windbird is just what she needs to escape her confinement. She must be stopped: for the sake of the universe, and because if she breaks out it will change time, and Benny may never be able to return home.
A series of increasingly fantastical adventures climaxes in the crushing of the Beastworker. Zeff retrieves the Primer she needs to navigate the Windbird, and returns Benny safely to his own time.