Runcible Jones Quintet

The Runcible Jones Quintet is a fantasy adventure series quintet, by author Ian Irvine, set on two twinned worlds for all ages from 10 to adult.
Setting.
Set on an Earth rather like our own but with two important differences, firstly magic is illegal though no one seems to know why, and power is vanishing from power stations all over the world. Iltior is an unspoiled world where everything is brighter and more beautiful, where everyone can use magic but science is forbidden. A world where people are being corrupted by resonances passing across the void from Earth, and the great magicians of Iltior are determined to do something about it.