The two boys are drawn towards a mysterious glowing ball, which instantly transports them to what appears to be more than a thousand years back in history.

The opportunistic Brad offers to help the Pope raise an army to overthrow the Roman authorities, ostensibly to cease oppression of the Christians, but mainly, in return for power, status and wealth for the cousins to rise in the new realms.

Simon goes along with the plan because he wants to free the slaves and promote equal status for non-Romans, and because he has fallen in love with a high-born girl.

However, Simon is quickly disillusioned when the new Church authorities begin forcing all people to convert to Christianity, or face death by the pendulum.

Together with Bos, a gladiator, and the staunch pagan, Curtius, both formerly on the side of the rebellion, the boys sail off on a ship towards the New World.